Serena Williams says motherhood has not lessened her competitive desire as she goes for another US Open win.

The 36-year-old is through to the quarter-finals at Flushing Meadow after beating Estonia’s Kaia Kanepi in the last 16 and meets eighth seed Karolina Pliskova for a place in the last four.

Williams is a six-times winner in New York and if she wins another title at the weekend it will be her 24th Grand Slam win putting her equal with Margaret Court as the all-time record winner.

She took time out of the sport to give birth to a baby daughter who turns a year old at the weekend, but the American says that motherhood has not dimmed her competitive spirit and her desire for more Grand Slam titles.

After beating Kanepi she said: “That desire has not gone down at all, and I don’t think it was capable of going up, because if it was at a 10, I was at a 15 or a 20 – and I’m still there.”

Williams has been in impressive form since returning to the WTA tour.

She missed the Australian Open at the start of the year but played the French Open, retiring through injury ahead of her round of 16 match with Maria Sharapova.

She did even better at Wimbledon, reaching the final at the All England Club but losing to Angelique Kerber in straight sets.

“It would be wonderful to win a Grand Slam while having a daughter, but it’s a lot of work,” she added.

“It takes a lot of work to win those tournaments. I’m only in my third one back. I’m going to continue to grind and see what happens.”

Williams is 1.30 to win the quarter-final with Pliskova 3.40. Williams is 2.50 to win the US Open with Madison Keys 5.00.