Second seed Jelena Jankovic advanced to the final of the Family Circle Cup with a 3-6 6-3 7-6 (7-5) victory over unseeded Venus Williams on Saturday.
The match lasted just over two and a half hours and ended in frustrating fashion for Williams, who lost to the Serbian at Wimbledon last year.
The tiebreak was tied 5-5 when Williams hit a forehand long.
On the next point, Jankovic ripped a shot near the sideline past Williams, who reacted as if the ball was out. However, the umpire checked the spot and determined the shot was in, giving Jankovic the dramatic win. Jankovic said: 'It was great to win a match like that.'
After missing most of 2006 with a wrist injury, Williams has begun to re-establish herself as a dominant player this season, winning the Tier III event at Memphis and going 14-3 overall.
A five-time Grand Slam champion, Williams proved she is at a level where she can play with Jankovic, who is ranked ninth in the world.
Williams said: 'I've had a long week here and did my best. I'm just happy to be going home. I'm very tired.'
Fatigue was a factor as Williams committed 13 double faults compared to just two for Jankovic.
Jankovic had struggled at the Family Circle Cup in the past, failing to advance beyond the second round in her four previous trips to the clay court event.
Jankovic will play Russian Dinara Safina in the final on Sunday.
The fourth-seeded Safina was leading countrywoman Vera Zvonareva 6-3 0-1 in their semi-final when Zvonareva retired with a wrist injury.
Zvonareva said: 'It hurt from the beginning of the match and it just got really bad to the point where I really couldn't perform.'
It marked the second match in a row that Safina's opponent retired due to injury. Safina won the first set against 10th seed Tatiana Golovin 6-3 before the Frenchwoman could no longer play because of an injured right ankle.
