GLASGOW, Scotland — Top-ranked Son Wan Ho finally looked like a title threat at the badminton world championships when he cooled off the hot Kidambi Srikanth on Friday.
Srikanth was on a 13-match winning streak, including two wins over Son. But Son got an early jump and held it all the way to win, 21-14, 21-18.
Also, defending two-time women's champion Carolina Marin was ousted by Japanese nemesis Nozomi Okuhara in a 93-minute hit-fest. Okuhara improved her win-loss record against the Olympic champion to 6-3.
Son's previous result of note this year was leading South Korea to Sudirman Cup glory, but he's exceeded that by making the semifinals at the worlds for the first time.
There he will play Lin Dan, who has reached his first semifinal since winning his record fifth world title in 2013.
In the other semifinal, Viktor Axelsen of Denmark will play defending two-time champion Chen Long, who eliminated fellow Chinese Tian Houwei, 21-12, 21-17.
Chen dominates his history with Axelsen, but the matchups are frequently tough. The Dane gave Chen memorable fights in the 2015 worlds quarterfinals and the 2016 China Open semifinals. They are the Olympic gold and bronze medalists.
Pusarla Sindhu of India guaranteed herself a third worlds medal after beating Sun Yu of China, 21-14, 21-9. She faces another Chinese, Chen Yufei, who beat 2013 champion Ratchanok Intanon, 14-21, 21-16, 21-12.
Okuhara, the All England champion last year, beat Marin, 21-18, 14-21, 21-15, winning six straight points in the last game for a deciding 19-13 lead.
Blocking her from a first worlds final is Saina Nehwal, the 2015 runner-up from India who showed superior fitness in outlasting Kirsty Gilmour of Scotland 21-19, 18-21, 21-15 after 74 minutes.
Srikanth looked nervous and allowed Son a good start that he carried into the second game. Srikanth's effort to keep up saw him fall out of his left shoe in one rally. Srikanth pulled to within 18-19 behind but hit the net twice, and was out.
"When Srikanth was coming back in the second game, I was very nervous but I told myself to remain calm," Son said.
Son has beaten Lin only twice in 12 matches, but made the Chinese superstar fight for nearly 90 minutes in April in the Malaysia semifinals.