Serena Williams admitted she was embarrassed by her crushing 6-0 6-2 defeat to Simona Halep at the WTA Finals in Singapore yesterday, her heaviest loss in 16 years.

The world number one, an 18-time Grand Slam winner, was 16 when she last suffered such a thrashing.

Halep, the 23-year-old from Romania, took apart her opponent’s serve in the first set, allowing Williams to win just six points on serve on the way to breaking three times.

Williams improved marginally in the second set, carving out six break points, but Halep saved them all and took her two break opportunities to seal a famous win.

“It was actually embarrassing I think describes the way I played,” Williams told reporters. “Yeah, very embarrassing.

“I’ve seen her play a lot. Like I said, she’s never played like this before.

“My serve was at best in the 10 and under division in juniors.”

Williams, 33, last failed to win more than two games in a completed match back in 1998 when she lost 6-1 6-1 to Joannette Kruger in Oklahoma City.

Halep, though, was able to celebrate the best win of her career and make it two wins out of two in the Red Group.

The win was her first over Williams, cutting off her 16-match winning streak at the WTA Finals.

“It’s the biggest match in my life, so I can’t put into words how I feel right now. I feel very happy. I just want to enjoy it,” Halep said.

“I don’t think it was her best day today, but I played really well, I was very aggressive and took the ball early, moved up the court very well, served very well. I’ve found my best tennis again. It’s crazy.”

Williams, though, who has won the tournament on her last three appearances, is now in danger of going out early, with a final match to come against Eugenie Bouchard.

Wimbledon finalist Bouchard was also heavily beaten, going down 6-1 6-3 to Ana Ivanovic.

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