Grass Wonder
American-bred Thoroughbred racehorse (1995–2025)
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Grass Wonder (Japanese: グラスワンダー, 18 February 1995 – 8 August 2025) was an American-bred Japanese-trained Thoroughbred racehorse and sire. In a racing career which lasted from 1997 until 2000 he won nine of his fifteen races including four Grade I races. He was the leading juvenile colt in Japan in 1997 when he was unbeaten in four races, culminating in a victory in the Asahi Hai Sansai Stakes. He missed most of his second season with injury problems but returned in autumn to win the Arima Kinen. He reached his peak as a four-year-old when he won the Takarazuka Kinen and a second Arima Kinen. He failed to win in three races in 2000 and was retired to stud. He had some success as a breeding stallion.
| Grass Wonder | |
|---|---|
Grass Wonder at Nakayama Racecourse on 26 December 1999 | |
| Sire | Silver Hawk |
| Grandsire | Roberto |
| Dam | Ameriflora |
| Damsire | Danzig |
| Sex | Stallion |
| Foaled | 18 February 1995[1] |
| Died | 8 August 2025 (aged 30) |
| Country | United States |
| Colour | Chestnut |
| Breeder | Phillips Racing Partnership & John Phillips |
| Owner | Hanzawa Co., Ltd. |
| Trainer | Mitsuhiro Ogata |
| Record | 15: 9-1-0 |
| Earnings | ¥691,646,000 |
| Major wins | |
| Keisei Hai Sansai Stakes (1997) Asahi Hai Sansai Stakes (1997) Arima Kinen (1998, 1999) Keio Hai Spring Cup (1999) Takarazuka Kinen (1999) Mainichi Okan (1999) | |
| Awards | |
| Japanese Champion 2-Year-Old Colt (1997) JRA Special Award (1999) Timeform rating: 126 | |
Background
Grass Wonder was a chestnut horse with a white star, standing 15.3½ hands high[2] bred in Kentucky by Phillips Racing Partnership & John Phillips, of the Darby Dan Farm.[3] He was sired by Silver Hawk, an American-bred colt who finished third in the 1982 Epsom Derby and later became a successful breeding stallion, siring the 1997 Epsom Derby winner Benny the Dip, the 1999 St Leger winner Mutafaweq and the leading American turf performer Hawkster.[4] Grass Wonder's dam Ameriflora was an unraced daughter of Danzig. She was a great-granddaughter of Soaring,[5] an American broodmare who was the ancestor of many major winners including Glorious Song, Saint Ballado, Rahy and Singspiel.[6]
The yearling was consigned to the Keeneland sale in September 1996 and was bought for $250,000 by Nobuo Tsunoda.[7] Grass Wonder was exported to Japan where he was trained by Mitsuhiro Ogata and was mainly ridden in his races by Hitoshi Matoba.[8][9]
Racing career
1997: two-year-old season
Grass Wonder began his racing by defeating nine opponents in a maiden race over 1800 metres at Nakayama Racecourse on 13 September 1997. A month later he followed up in the Ivy Stakes over 1400 metres at Tokyo Racecourse, winning from Machikane Sanshiro. In November he was moved up in class for the Grade II Keisei Hai Sansai Stakes over the same course and distance and won from Machikane Sanshiro and Courir Cyclone.[10] On his final start of the season, Grass Wonder was one of fifteen colts to contest Japan's most prestigious race for juveniles, the Asahi Hai Sansai Stakes over 1600 metres at Nakayama on 7 December. Ridden by Matoba, he won by two and a half lengths from Meiner Love (later to win the Sprinters Stakes) who took second ahead of Figaro and Agnes World.[11]
Grass Wonder was voted Japanese Champion 2-Year-Old Colt of 1997 at the JRA Awards.[12]
1998: three-year-old season
As a foreign-bred horse, Grass Wonder was not eligible to race in many of the major Japanese races for three-year-olds, and when he sustained a leg injury in March 1998 it was decided to reserve him for an autumn campaign.[citation needed] He made his first appearance of the year he finished fifth behind Silence Suzuka in the Grade II Mainichi Okan over 1800 metres at Tokyo in October.[13] In the following month he was moved up in distance for the Grade II Copa Republica Argentina over 2500 metres at Tokyo and finished sixth behind Yusei Top Run.[10]
Despite his lack of form in 1998, Grass Wonder was one of sixteen horses selected to run in the Arima Kinen over 2500 metres at Nakayama on 27 December. His opponents included Air Groove (Tenno Sho (autumn)), Matikanefukukitaru (Kikuka Sho), Mejiro Bright (Tenno Sho (spring)), Mejiro Dober (Shuka Sho, Queen Elizabeth II Commemorative Cup), Offside Trap (Tenno Sho (autumn)), Seiun Sky (Satsuki Sho, Kikuka Sho), Silk Justice (Defending Champion), Stay Gold and Yusei Top Run. Grass Wonder won by half a length from Mejiro Bright with a gap of two and a half lengths back to Stay Gold who took third place ahead of Seiun Sky.[14]
1999: four-year-old season

Grass Wonder began his third season in the Grade II Keio Hai Spring Cup over 1400 metres at Tokyo on 15 May. He won by three quarters of a length from Air Jihad, to whom he was conceding four pounds. The unplaced horses included Phalaenopsis (Oka Sho, Shuka Sho) and the Godolphin challenger Lend A Hand (Gran Criterium).[15] On 13 June over 1600 metres Grass Wonder faced Air Jihad at level weights in the Yasuda Kinen. He was beaten a nose by his rival with the pair finishing two and a half lengths clear of Seeking The Pearl (Prix Maurice de Gheest) in third place. Grass Wonder returned to middle distances for the Takarazuka Kinen over 2200 metres at Hanshin Racecourse on 11 July and was matched for the first time against Special Week, a colt who had won the Tokyo Yushun in 1998 and the spring edition of the Tenno Sho. The other runners included Matikanefukukitaru and Stay Gold. Grass Wonder defeated Special Week with a gap of seven lengths back to Stay Gold in third.[16]
After a break of almost three months, Grass Wonder returned for the Grade II Mainichi Okan over 1800 metres at Tokyo on 10 October and won from Meisho Odo and Embrasser Moi.[10] On 26 December at Nakayama, Grass Wonder attempted to become the fourth horse following Speed Symboli, Symboli Rudolf and Oguri Cap to win back-to-back runnings of the Arima Kinen. His main opponents in the fourteen runner field included Mejiro Bright, Narita Top Road, Phalaenopsis, Special Week, Stay Gold, Symboli Indy (NHK Mile Cup) and T. M. Opera O (Satsuki Sho). The race produced a dramatic finish with the lead changing hand several times in the last 200 metres, but Grass Wonder prevailed by a nose and a neck from Special Week and T. M. Opera O with Tsurumaru Tsuyoshi half a length away in fourth.[17]
For his efforts over the course of the season, Grass Wonder was given a special award at the JRA Awards for 1999.[citation needed]
2000: five-year-old season
Grass Wonder remained in training as a five-year-old colt but failed to reproduce his best form. He finished sixth behind Leo Ryuho in the Grade II Nikkei Sho over 2500 metres at Nakayama on 26 March and then ran unplaced behind the filly Stinger in the Keio Hai Spring Cup. In his final race the horse ran for the second time in the Takarazuka Kinen and finished sixth of the eleven runners behind T. M. Opera O.[18]
Racing form
The following racing form is based on information available on JBIS search[19] and netkeiba.com.[20]
| Date | Track | Race | Grade | Distance (Condition) |
Entry | HN | Odds (Favored) |
Finish | Time | Margins | Jockey | Winner (Runner-up) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1997 – two-year-old season | ||||||||||||
| Sep 13 | Nakayama | 3YO debut | 1800m(Firm) | 10 | 9 | 1.5(1) | 1st | 1:52.4 | −0.5 | Hitoshi Matoba | (Bildschon) | |
| Oct 12 | Tokyo | Ivy Stakes | OP | 1400m(Firm) | 9 | 8 | 1.4(1) | 1st | 1:21.9 | −0.8 | Hitoshi Matoba | (Machikane Sanshiro) |
| Nov 8 | Tokyo | Keisei Hai Sansai Stakes | 2 | 1400m(Firm) | 9 | 2 | 1.1(1) | 1st | 1:21.9 | −1.0 | Hitoshi Matoba | (Machikane Sanshiro) |
| Dec 7 | Nakayama | Asahi Hai Sansai Stakes | 1 | 1600m(Firm) | 15 | 11 | 1.3(1) | 1st | R1:33.6 | −0.4 | Hitoshi Matoba | (Meiner Love) |
| 1998 – three-year-old season | ||||||||||||
| Oct 11 | Tokyo | Mainichi Okan | 2 | 1800m(Firm) | 9 | 6 | 3.7(2) | 5th | 1:46.4 | 1.5 | Hitoshi Matoba | Silence Suzuka |
| Nov 7 | Tokyo | Copa Republica Argentina | 2 | 2500m(Firm) | 18 | 13 | 3.0(1) | 6th | 2:33.5 | 0.6 | Hitoshi Matoba | Yusei Top Run |
| Dec 27 | Nakayama | Arima Kinen | 1 | 2500m(Firm) | 16 | 2 | 14.5(4) | 1st | 2:32.1 | –0.1 | Hitoshi Matoba | (Mejiro Bright) |
| 1999 – four-year-old season | ||||||||||||
| May 15 | Tokyo | Keio Hai Spring Cup | 2 | 1400m(Firm) | 18 | 5 | 2.1(1) | 1st | 1:20.5 | –0.1 | Hitoshi Matoba | (Air Jihad) |
| Jun 13 | Tokyo | Yasuda Kinen | 1 | 1600m(Firm) | 14 | 7 | 1.3(1) | 2nd | 1:33.3 | 0.0 | Hitoshi Matoba | Air Jihad |
| Jul 11 | Hanshin | Takarazuka Kinen | 1 | 2200m(Firm) | 12 | 5 | 2.8(2) | 1st | 2:12.1 | –0.5 | Hitoshi Matoba | (Special Week) |
| Oct 10 | Tokyo | Mainichi Okan | 2 | 1800m(Firm) | 10 | 8 | 1.2(1) | 1st | 1:45.8 | 0.0 | Hitoshi Matoba | (Meisho Odo) |
| Dec 26 | Nakayama | Arima Kinen | 1 | 2500m(Firm) | 14 | 7 | 2.8(1) | 1st | 2:37.2 | 0.0 | Hitoshi Matoba | (Special Week) |
| 2000 – five-year-old season | ||||||||||||
| Mar 26 | Nakayama | Nikkei Sho | 2 | 2500m(Firm) | 10 | 7 | 1.3(1) | 6th | 2:36.3 | 0.9 | Hitoshi Matoba | Leo Ryuho |
| May 14 | Tokyo | Keio Hai Spring Cup | 2 | 1400m(Firm) | 18 | 8 | 2.4(1) | 9th | 1:21.6 | 0.6 | Hitoshi Matoba | Stinger |
| Jun 25 | Hanshin | Takarazuka Kinen | 1 | 2200m(Firm) | 11 | 11 | 2.8(2) | 6th | 2:14.7 | 0.9 | Masayoshi Ebina | T M Opera O |
- R on the time indicates that this was a record time
Retirement and stud record

Grass Wonder was retired from racing to stand at the Shadai Stallion Station in Hokkaido. He later moved to the Breeders' Stallion Station where he was based in 2015.[2][21]
The best of his offspring have included:
- Sakura Mega Wonder (2003), won seven races including the Kinko Sho[22]
- Screen Hero (2004), won five races including the Japan Cup[23]
- Earnestly (foaled 2005), won 10 races including the Takarazuka Kinen[24]
- Seiun Wonder (2006), won 4 races including the Asahi Hai Futurity Stakes[25]
Death
In popular culture
An anthropomorphized version of Grass Wonder appears in Umamusume: Pretty Derby, voiced by Rena Maeda.[26][28]
Pedigree
| Sire Silver Hawk (USA) 1979 |
Roberto (USA) 1969 |
Hail To Reason | Turn-To |
|---|---|---|---|
| Nothirdchance | |||
| Bramalea | Nashua | ||
| Rarelea | |||
| Gris Vitesse (USA) 1966 |
Amerigo | Nearco | |
| Sanlinea | |||
| Matchiche | Mat de Cocagne | ||
| Chimere Fabuleuse | |||
| Dam Ameriflora (USA) 1989 |
Danzig (USA) 1977 |
Northern Dancer | Nearctic |
| Natalma | |||
| Pas de Nom | Admiral's Voyage | ||
| Petitioner | |||
| Graceful Touch (USA) 1978 |
His Majesty | Ribot | |
| Flower Bowl | |||
| Pi Phi Girl | Raise a Native | ||
| Soaring (Family 12-c)[6] |