1979 Thomas Cup knockout stage

The first semifinal tie pitted Denmark against India in what might have been expected to have been a very close encounter. Typically talented, Danish squads had also, typically, struggled in the tropical heat and humidity. This time, however, Denmark came through in the uncongenial climate 7–2; the pivotal match probably being wily veteran Svend Pri's inspiring victory over the much younger Prakash Padukone (less than a year before Padukone's triumph at the All-England Championships).

The second semifinal presented Japan with the daunting task of facing a powerhouse Indonesian squad in an Indonesian setting. Moreover, these Japanese players, especially in singles, were not as internationally accomplished as the highly competitive Japanese stars of a decade earlier. It came as quite a surprise, then, when Japan's number one singles player, Kinji Zeniya, began the series by racing off to a 14–9 lead on reigning All-England champion Liem Swie King. This, however, was as close to a victory as Japan came. King recovered to win the game 17–16 and nearly blanked Zeniya in the second game. Fighting hard throughout, the Japanese were successively worn down by better players who were also more accustomed to the tropical conditions. It was the first time that Japan had been on the losing side of a Thomas Cup shut-out. Thus for the fourth time, the third in a championship tie, Indonesia and Denmark squared-off in Thomas Cup competition.^[3][4]

Denmark 7	Istora Senayan 26–27 May 1979 [5][6]		India 2
1 2 3 1 Svend Pri Syed Modi 15 11 15 6     2 Morten Frost Prakash Padukone 10 15 15 18     3 Flemming Delfs / Steen Skovgaard Prakash Padukone / Uday Pawar 17 14 12 15 15 6   4 Steen Fladberg / Morten Frost Partho Ganguli / Pradeep Gandhe 17 14 15 5     5 Flemming Delfs Partho Ganguli 15 10 10 15 15 5   6 Morten Frost Syed Modi 6 15 7 15     7 Svend Pri Prakash Padukone 17 14 15 3     8 Steen Fladberg / Morten Frost Prakash Padukone / Uday Pawar 15 11 15 3     9 Flemming Delfs / Steen Skovgaard Partho Ganguli / Pradeep Gandhe 12 15 15 8 10 15

Indonesia 9	Istora Senayan 28–29 May 1979 [7][8]		Japan 0
1 2 3 1 Liem Swie King Kinji Zeniya 11 16 15 1 15   2 Lius Pongoh Masao Tsuchida 15 5 18 13     3 Tjun Tjun / Johan Wahjudi Nobutaka Ikeda / Shoichi Toganoo 15 6 15 4     4 Christian Hadinata / Liem Swie King Yoshitaka Iino / Masao Tsuchida 15 2 15 5     5 Rudy Hartono Toshihiro Tsuji 15 8 15 1     6 Liem Swie King Masao Tsuchida 11 15 15 2 15 4   7 Lius Pongoh Kinji Zeniya 11 15 15 7 15 4   8 Tjun Tjun / Johan Wahjudi Yoshitaka Iino / Masao Tsuchida 15 8 15 6     9 Christian Hadinata / Liem Swie King Nobutaka Ikeda / Shoichi Toganoo 15 4 15 5

Though Svend Pri was 34 and by this time only the third ranked singles player in Denmark, his record of winning clutch singles matches in tropical conditions had earned him a slot in the top two singles positions. Indonesia might have placed the iconic Rudy Hartono (two months shy of 30) in a similar position in its lineup and thus effected a sequel to their long rivalry. It was not to be, as Indonesia placed Hartono in the third singles position. Nevertheless, in "veteran" Iie Sumirat, only a year younger than Hartono and, like Pri, something of a showman, Pri drew a worthy adversary. Their opening contest, the most interesting of the tie, was won by Sumirat 15–10 in the third game. Except for a three-game win by Sumirat over rising star Morten Frost on the second night, every other match was routinely taken by Indonesia. Flemming Delfs, whose play in the tropics was almost invariably a full level below its European standard, lost tamely to Hartono, and only one doubles game in eight was close.^[9] Thus for the second straight time Indonesia shut-out its final opponent in Thomas Cup, thereby winning the Cup for the seventh time in eight attempts.

Indonesia 9	Istora Senayan 1–2 June 1979 [10][11]		Denmark 0
1 2 3 1 Iie Sumirat Svend Pri 11 15 15 7 15 10   2 Liem Swie King Morten Frost 15 3 15 6     3 Tjun Tjun / Johan Wahjudi Flemming Delfs / Steen Skovgaard 15 2 15 3     4 Christian Hadinata / Liem Swie King Steen Fladberg / Morten Frost 15 8 15 2     5 Rudy Hartono Flemming Delfs 15 10 15 2     6 Iie Sumirat Morten Frost 11 15 15 9 15 8   7 Liem Swie King Svend Pri 15 8 15 1     8 Tjun Tjun / Johan Wahjudi Steen Fladberg / Morten Frost 15 9 15 5     9 Christian Hadinata / Liem Swie King Flemming Delfs / Steen Skovgaard 17 16 15 4