WIMBLEDON, England — Reilly Opelka still is getting used to some aspects of visiting Britain.
The bed frame where he stayed during a Wimbledon tuneup tournament that wasn't quite big enough for the 6-foot-11 (2.11-meter) American, for example. The lack of air conditioning compared to back home in Florida. As for the grass-court tennis? Opelka is increasingly comfortable with that, as demonstrated by a 7-5, 3-6, 4-6, 6-4, 8-6 second-round victory over three-time major champion Stan Wawrinka at the All England Club on Wednesday.
"Every year I come here, and, like, 'Why is there no AC?' They're, like, 'Oh, it's never hot here.' Every year, it's over 80 degrees!" Opelka said.
He is ranked 63rd and is unseeded for his main-draw debut at Wimbledon, where he won the 2015 junior title.
But against a far-more experienced and far-more accomplished player, he pounded eight of his 23 aces and saved both break points he faced in the last set, fending off 10 of Wawrinka's 12 break chances in all. At 6-all in the fifth, Opelka erased a break chance with a 140 mph service winner, then followed with two more serves Wawrinka failed to put in play, at 133 mph and 137 mph.
It was Opelka's ability to adjust his style, serve-and-volleying only three times in the final set, and to hang in there on longer exchanges that made this upset possible.
"I've always been a pretty good mover. Underrated, actually," said the 21-year-old Opelka, participating in only his fourth major tournament. "I think sometimes when I play guys for the first time, they don't expect it. It helps me win so many points, being able to (track) down some extra balls, especially in the key moments."
It was the 22nd-seeded Wawrinka's groundstrokes who failed him, with four errors that helped Opelka earn the only service break of the fifth set in the last game. When it ended, Opelka yelled, "Come on!" and then pounded his chest.
"At the end, he went for it," Wawrinka said. "He went bigger than me, and he deserved to win."
So maybe it's time for Opelka to stop downplaying his chances this fortnight.
Before facing Wawrinka, Opelka called it a "brutal matchup."
Afterward, Opelka referred to Wawrinka as "the main attraction."
On Friday, in his first appearance in third round of any Grand Slam tournament, Opelka will face someone else he labeled "the favorite" — 2016 Wimbledon runner-up Milos Raonic, who is seeded 15th.
"He's as good as it gets when it comes to grass, so really, really excited for that matchup," Opelka said. "It's going to be a really big challenge playing a guy as good as he is on this surface."
The same could be said of Opelka right now.
"He plays aggressive. He goes for it. He tries to keep you off-balance. He's hard to get a rhythm on, because not only does he finish things off pretty quickly with his serve and getting ahead that way, but he's constantly swinging for his other shots," said Raonic, who entered Wimbledon dealing with a lingering back issue and had some issues with his left calf during Wednesday's straight-set win over Robin Haase. "He doesn't really hold back. It's hard to sort of work yourself into the points."
SERENA & ANDY
As it is, the All England Club was concerned about keeping British star Andy Murray away from crowds around the grounds on his way to and from his first men's doubles match with partner Pierre-Hugues Herbert, which will be on Thursday on an as-yet-unannounced court.
Imagine what sort of rush there will be to try to catch a glimpse of Murray and his mixed doubles partner, Serena Williams.
"Hope they put them on Centre Court," 2018 French Open champion Simona Halep said, "because everyone is going to watch it."
In Wednesday's draw for mixed doubles, Williams and Murray were picked to face Andreas Mies of Germany and Alexa Guarachi of Chile in the first round.
Williams, who owns 23 Grand Slam singles titles, and Murray, who owns three, are as high-profile a team as could be.
He is limited to playing doubles at the moment as he returns from an operation for a hip replacement.
"I mean, good luck to everybody else," two-time Australian Open champion Victoria Azarenka said. "It's going to be a tough, tough, tough one to beat. They both take it seriously. But I feel like it's going to be just a pleasure for people to watch. It's going to be historic. So I'll be definitely watching, as well."
HALEP VS. AZARENKA
A pair of former No. 1s will match up in the third round on Friday when Simona Halep and Victoria Azarenka face each other for the fifth time. Each has won two of the previous meetings.
Azarenka, who is ranked 40th, had quite a busy Wednesday. She dropped the opening two games of her singles match against Ajla Tomljanovic, before taking 12 games in a row for a 6-2, 6-0 victory. Then she and Ash Barty, the current No. 1 in singles, went out and won their first-round match in women's doubles.
Halep, the No. 7 seed, got past Mihaela Buzarnescu 6-3, 4-6, 6-2 in an all-Romanian match.
What will determine how she fares against Azarenka?
"The key," Halep said, "is the mental part."