Top-seed Serena Williams was knocked out of the ASB Classic in Auckland in the second round yesterday by fellow US athlete Madison Brengle.

World number two Williams was beaten 6-4 6-7 (7/3) 6-4 by the 26-year-old, who is 70 places below her in the current rankings.

It was the biggest win of Brengle’s career and her first against a top-three opponent, with Williams making 88 unforced errors.

“I really think I played — I’m trying to think of a word that’s not obscene — but that’s how I played,” Serena said.

“Eighty eight unforced errors is too much, just way too many. It’s a lot. I can’t expect to win hitting that many errors.

“I couldn’t get used to the wind; my opponent was playing in the same conditions, and maybe the wind was more suited for her game, but it was really annoying me for whatever reason.”

There was no such problem for Serena’s sister Venus, seeded second, as she saw off wildcard Jade Lewis 7-6 (7/2) 6-2 in her opening match.