India's Saina Nehwal kept her Super Series Finals chances alive with one of the most remarkable wins of her career Thursday — a 23-21, 9-21, 21-12 triumph against world champion Carolina Marin. Nehwal had been unable to train for three weeks due to an Achilles injury and lost her opening group match heavily Wednesday. But 24 hours later, she saved a game point in the first game, recovered from a disastrous second, and frustrated the world's best attacking woman player in an amazing third. The Indian was helped by noisy support from a sizeable expatriate crowd, and by a strangely patchy performance from the Spaniard toward the end, when she was unable to finish a number of rallies after she had created good openings. "My god, I didn't expect this," said Nehwal. "I never thought I would win, and I had no plan. And I really never expected to play so well against Carolina. "I didn't do any kind of running before coming here, and I thought I would be playing with my dog at home this weekend." Instead, if Nehwal overcomes the winless Tai Tzu Ying of Taiwan Friday, she could reach Saturday's semifinals. That though depends on how well her troublesome Achilles, with its related aches and pain, recovers. Marin, meanwhile, now has to win her last group match, against Nozomi Okuhara of Japan, who is unbeaten. If she does it could leave three players with two wins, and cause a countback of games won and lost. Earlier Chen Long, the men's world number one from China, who is making a good job of escaping from the shadow of the greatest player of all time, made certain of qualifying for the semis with a solid second win. He did that with a gear-changing 21-17, 21-12 win over Hu Yun, a boyhood friend from Hubei province, who is representing Hong Kong. Already the winner of seven major titles this year, Chen is an increasingly hot favorite to score an eighth in Dubai, and a successful title defense in the tour's flagship event is one of the very few things which his legendary compatriot, Lin Dan, twice the Olympic men's singles champion, has not managed. Hu surprisingly took a 9-5 lead in the first game, but when Chen increased the speed of the rallies and combined it with some brilliant, breath-taking defense, he pulled back the deficit steadily. When he hurtled to a 9-0 lead in the second game, it effectively ended the contest. "These things are quite normal," claimed Chen. Earlier another Chinese player, Wang Yihan, the former leading woman, resisted defeat as resolutely as the repeated questions about when she will retire, coming from a game and 16-17 down to beat Ratchanok Intanon in a tussle of former world champions. Wang played close to her best when she was in danger in the second game, taking five out of the last seven points to rescue herself and then getting on top and winning 19-21, 21-19, 21-11. She now qualifies for the semis while Intanon will contest the other available place with Wang Shixian, China's former world No. 1.