Serena Williams bounced back from her embarrassing loss to Simona Halep by beating Eugenie Bouchard in comprehensive fashion at the WTA Finals.
The world number one suffered her worst defeat for 16 years in Singapore yesterday, winning just two games.
It was the two-time defending champion’s first loss in 17 matches at the end-of-season event and left her relying on other results going her way to reach the semi-finals.
She did her bit, needing only 57 minutes to see off Bouchard 6-1 6-1, a result that also ensured Halep became the first woman to qualify for the last four.
Halep needed Bouchard to win only one game, and the 20-year-old Canadian fought back from 0-40 to hold serve in the opener.
But from there it was a miserable afternoon for Bouchard, who came into the tournament under-prepared because of a thigh problem and has lost all her round-robin matches in straight sets.
The final match in the red group comes on Friday between Halep and Ana Ivanovic, with a straight-sets win for the Serbian enough to put her through to the semi-finals and eliminate Williams.
In the white group, Caroline Wozniacki made it two wins out of two by defeating Agnieszka Radwanska 7-5 6-3.
It was a high-quality match but Wozniacki, who had battled for more than three hours to see off Maria Sharapova in her opening clash, was the stronger in the end.
The Dane, who is the lowest-ranked player at the event, said on the tournament website: “I knew from the start this wasn’t going to be an easy match, it was going to be a match with a lot of long rallies and some incredible shot-making.
“I came out there and was a little bit nervous and a few times early on I was thinking, ’Aga, how did you make that ball?”’
Wozniacki is still not assured of a spot in the last four because Wimbledon champion Petra Kvitova defeated Sharapova 6-3 6-2 in the other match, meaning all four women can still qualify.
It was Kvitova’s first victory over Sharapova in six attempts, a run dating back three years.