Serena Williams triumphed over Maria Sharapova in a US Open first-round contest as one-sided as their 15-year rivalry.

Williams, the 23-time grand slam champion, has now won 20 of their 22 meetings following a thumping 6-1 6-1 victory.

It was the pair's first encounter since January 2016, and was all the more eagerly-anticipated after Williams pulled out of a scheduled meeting at last year's French Open through injury.

Sharapova is nowhere near the player who beat Williams in the 2004 Wimbledon final – and also won their next match the same year – but despite the scoreline she did not play at all badly.

The Russian, 32, got a healthy 73 per cent of her first serves in. One fierce cross-court winner on the run even had Williams applauding.

But Sharapova could barely lay a glove on Williams, who turns 38 this month and remains tantalisingly within touching distance of Margaret Court's record of 24 major titles.

Victory was wrapped up when a Sharapova return floated long after only 59 minutes.

Williams said: "Obviously I was going against a player who has won five grand slams so it was never going to be easy, and every practice after that was super intense because it was such a tough draw.

"She's such a good player, and you have to be super focused, so every time I come up against her I have to play my best tennis."

Williams, who has now won 19 matches in a row against Sharapova, added: "I just feel like her game really matches up well against mine.

"I always said her ball somehow lands in my strike zone. I don't know. It's just perfect for me."

Sharapova, champion here in 2006, was philosophical in defeat.

"I thought she played well, I thought she served really well and found her spots really well," she said.

"It didn't feel like we got into too many long rallies. I think the one-two punch, she won a majority of those points.

"But the bottom line is I believe in my ability. You can write me off. There are many people that can write me off, especially after going down 6-1 6-1 in the first round of the US Open.

"As long as it's not the person that's inside of you, you'll be OK."

French Open champion Ashleigh Barty, seeded second, survived a scare after dropping the first set in double-quick time against Zarina Diyas.

The Australian, opening proceedings in the Arthur Ashe Stadium, eventually hit back to win 1-6 6-3 6-2.

"I just didn't give myself a chance in that first set," said Barty. "It was sort of appalling, I probably made a set's worth of errors."

Third seed Karolina Pliskova needed a pair of tie-breaks to get past Czech qualifier Tereza Martincova in the first match on Louis Armstrong.

Angelique Kerber was a surprise casualty, the 2016 champion storming back after losing the first set to Kristina Mladenovic, but then bowing out 7-5 0-6 6-4.

Kerber, last year's Wimbledon winner, said: "I tried everything I could, and in the last 10 days I prepared as good as I can.

"This is tennis, this is sport, and we have to deal with this. I will deal with this as good as I can."

Two-time champion Venus Williams eased through with a 6-1 6-0 victory over Chinese world number 38 Saisai Zheng.