Serena Williams says her motivation to win major trophies remains as high as ever in motherhood after reaching the US Open quarter-finals.
Williams, whose daughter Olympia turned one on Saturday, is aiming to win a record-equalling 24th Grand Slam title in New York.
The 36-year-old American former world number one is playing her seventh tournament since giving birth.
"That desire has not gone down at all," she said.
"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.