Going head-to-head with sister Venus for the 30th time brought out the best in Serena Williams as she hit top form at the US Open.
Just before the match, Serena shared a video on Instagram from exactly a year ago when she was in labour preparing to give birth to daughter Olympia.
There will be further tests to come that will show whether she is totally back to her best, but there was little to fault as she raced to a 6-1 6-2 victory in just an hour and 11 minutes, equalling the most one-sided match in their long history.
Venus and Serena Williams embrace at the net after the latter wins the US Open third round tie
The sisters shared an embrace at the net before a muted wave to the crowd from Serena, who will next face Estonia's Kaia Kanepi.
'It's not easy,' said the 36-year-old. 'She's my best friend, she means the world to me and she's so supportive of my career and I'm extremely supportive of her career. Every time she loses I feel like I lose. I love her with all my heart and she's the only reason I'm still out here. I owe everything to her.'
Serena rated it her best performance since returning to the tour in March, but Venus went a step further, declaring this Serena's best ever display against her.
'I don't think I did a lot wrong,' said the 38-year-old, who has had a disappointing 2018. 'But she just did everything right. Obviously that level is definitely where she's going to want to stay during this whole tournament.'
Serena (right) plays a ferocious forehand past her sister en route to winning in just 71 minutes
Venus, 38, struggled to cope with her sister's game as she crashed out of the tournament
The score matched Serena's victory in Charleston five years ago, while the loser had always won at least six games in their 15 previous slam meetings. Serena now leads the overall head-to-head 18-12 and has won nine of their last 11 clashes.
Although they have got used to