Despite a mid-match lapse, Danai summoned all his energies in the final set to subdue an inspired Go Soeda of Japan 6-0 2-6 6-2 to advance to the final where he takes on South Korean top seed Lee Hyung-taik, who crushed Cecil Mamiit of the Philippines 7-5 6-0.

Second-seeded Sonchat and Sanchai earlier tamed South Koreans Jun Woong-sun and Kim Sun-young 6-1 6-3 in the doubles semi-final to set up a showdown with top seed and multiple Grand Slam champions Leander Paes and Mahesh Bhupathi, who moved past Mamitt and Federic Taino 6-2 6-4.

Danai's appearance in the final means he can help Thailand win back-to-back men's singles gold for Thailand after Paradorn Srichaphan, who withdrew with a wrist injury, won in Busan four years ago. The Ratiwatanas, meanwhile, are vying to become the second Thai pair to claim the doubles gold medal after Paradorn and brother Narathorn triumphed in the 1998 edition in Bangkok.

"I'm so happy to win this match. After the first set I slowed down the game because I felt stiff on my right thigh. But after I got some massage from the therapist, I felt better and played to my level again in the third set," said Danai, who trails Lee 5-1 in their head-to-head meetings.

Meanwhile, Indian favourite Sania Mirza stunned Chinese top seed Li Na with a 6-2 6-2 victory on Tuesday to secure her place in the women's singles final.

The day belonged to Mirza who plays Zheng Jie from China in today's final after the second seed downed Japan's Aiko Nakamura 6-3 6-2.

World No 66 Mirza said she kept expecting Li to come charging back.

"I kept thinking she is 21 in the world so she can definitely come back here at any second. But I just tried to do what I knew I had to do," she said.

Li said that she was underprepared for the match and surprised by Mirza's powerful ground strokes.

"I felt as though the ball was coming off my racquet really well. She just played well. She deserved to win," the top seed said.

Li, 24, had been hot favourite to win this tournament after she made history at Wimbledon earlier this year when she became the first Chinese woman to reach the quarter-finals of a Grand Slam.

But she seemed rattled by the large, cheering Indian crowd, and never had a grip on the match.

Mirza, seeded four, broke Li in the first game and again in the fifth before taking a 5-2 lead and serving out for the set.

After a marathon, energy-sapping game in the second set, Mirza finally broke for a 2-1 lead which the Indian said was crucial to winning the match.

Li appealed at one stage to her entourage for help as Mirza, backed by screaming fans, broke again for 4-1 when Li completely missed a routine forehand.

They both held serve leaving the Indian to serve out the match.

Mirza agreed that the crowd had helped her.

"It's amazing. It's the biggest turnout today, more people than ever."

She has another chance at gold when she teams with Leander Paes in the mixed doubles semi-finals later yesterday.

In the men's singles, Lee conceded that the first set had been tough, saying he felt sluggish and describing Mamiit's style of play as aggressive and tenacious.

"In the second set I felt better and I was playing better and in the end I won relatively easily," he said.

Lee is gunning for his second gold here after helping South Korea win the team event.

The top seed and Asian Games 2002 silver medallist opened his semi-final match in ominous style, breaking the sixth seed in the second game to love with a couple of booming forehands to take a 2-0 lead.

But the US-based Mamiit recovered straight away, breaking back, with a tough struggle ensuing before Lee broke again to take the first set 7-5.

Sensing victory and with Mamiit tiring, Lee stepped up the momentum breaking the world number 187 three times including in the final game, winning 6-0.

In the men's doubles, Paes and Bhupathi moved into the finals with a 6-2 6-4 victory over Mamiit and Frederick Tain from the Philippines.

In the mixed doubles, Japan's Satoshi Iwabuchi and Akiko Morigami defeated Taiwan's third seeds Lu Yen Hsun and Hsieh Su Wei 7-6 (7/5) 6-3.