Samantha Stosur returns a shot to Urszula Radwanska of Poland. Stosur says she is more relaxed on the grasscourts this year. Source: AP

Yet to drop a set after cruising past Urszula Radwanska 6-3 6-4 in the second round, Stosur faces unseeded Coco Vandeweghe tonight fully aware of the formidable challenge the big-hitting American presents.

Stosur beat Vandeweghe en route to US Open glory in New York four years ago but has come up short in their past two encounters, including at the Australian Open in January.

Vandeweghe’s 7-6 (7-5) 6-4 removal of 11th seed Karolina Pliskova yesterday provided another reminder of the arsenal the world No 47 possesses.

“It’s going to be a tough one. I’ve lost the last couple of times we’ve played but had some really close matches,” Stosur said after advancing to the third round at the All England for only the third time in 13 visits.

“I know she’s going to be out to play some big tennis. She always does. She’s one of those opponents that can be very dangerous but she can also be a little bit erratic. So it’s a matter of being really conscious of taking care of your own service games and doing what you need to be doing and any opportunity on her service games, you’ve got to try and take because you may not get too many.”

Stosur, who has excelled not only on US hardcourts but even more consistently on European clay, attributes her miserable Wimbledon record to never really getting full value for her big second-serve kicker on grass. But the 22nd seed believes the heat this year is proving to her advantage.

“The weather is making the court play quite hard,” she said. “You are able to hit with a bit more topspin and a few more kick serves and you get a bit more reaction out of it because it is so hard and dry. So at the moment I’m liking it.”

But the biggest factor behind her grasscourt revival, having not won a match on the surface in a year before this week, is Stosur’s more relaxed approach.

The 31-year-old admits to having been too uptight in past trips to London’s hallowed lawns and opted to relieve the pressure on herself this campaign.

“There’s always nerves and jitters at certain points of time, but I don’t think that ever goes away if you care about what you’re doing,” Stosur said.

“I’m just trying to play the way I want to play out there and enjoy it, and it’s working.”

Serena Williams and Maria Sharapova hardly broke sweat as they cruised into the third round with comfortable victories.

World No 1 Williams eased to a 6-4 6-1 win over Hungary’s Timea Babos, while Sharapova took just 65 minutes to see off the world No 123 Richel Hogenkamp in a 6-3 6-1 cakewalk. She will play Romania’s Irina-Camelia Begu, the 29th seed, in the next round. Williams, 33, will play Britain’s Heather Watson for a place in the last 16.

“I’m definitely playing well, which I never say, but I had two really tough matches straight off the bat so I had to pick up my game,” Williams said.

“Timea, she plays so well, she has such a huge serve, so I was like, ‘Oh my God, it’s not going to be easy for me’.

“I really had no option but to play well so far. But I’d like to ­believe I have a lot of room to ­improve.”

On current evidence, she is approaching peak form at just the right time.

Williams, who could face a fourth- round showdown with sister Venus, was never troubled by the outclassed Babos after breaking her in the opening game of the match.

Meanwhile, seventh-seeded Ana Ivanovic of Serbia crashed out, losing her second-round match 6-3 6-4 to American qualifier Bethanie Mattek-Sands.

Ivanovic had reached the semi-finals at Wimbledon in 2007 and was heavy favourite to beat the world No 158.

Mattek-Sands will face Swiss teenager Belinda Bencic for a place in the last 16.

AAP