Serena Williams began her U.S. Open quarter-final tentatively. Her shots lacked their usual sting, her attitude its usual conviction.
She was facing the last player she lost to at Flushing Meadows, and perhaps that was the problem. After just 20 minutes Tuesday night, Williams was in danger of trailing by two service breaks. Not much later, the outcome was no longer in doubt, because the 23-time Grand Slam champion suddenly was in complete control.
Williams put aside some early shakiness and an early deficit, turning things around with an eight-game run en route to a 6-4, 6-3 victory over No. 8 seed Karolina Pliskova for a spot in the semifinals.
Pliskova is a big server and hitter in her own right, someone who briefly spent time at No. 1 in the WTA rankings and was the runner-up at the U.S. Open in 2016, when she beat Williams in the semifinals. The 36-year-old American did not compete in New York a year ago, because she gave birth to her daughter during the tournament.
This time, Williams' semifinal opponent will be No. 19 seed Anastasija Sevastova of Latvia, who surprisingly beat defending champion Sloane Stephens 6-2, 6-3 earlier Tuesday.
It did take Williams a little while to get going as she pursues a seventh U.S. Open title. Consider this: 22 of her 30 unforced errors came in the first set against Pliskova.
With her older sister, Venus — the woman she beat in the third round — in her guest box, Williams looked tight. Her timing was off. She put a backhand into the net to get broken to 2-1 at the outset. Then, down 3-1, she faced three break points; if Pliskova won any, she would have led 4-1. But Pliskova did not manage to put any of Williams' serves in play on those key points.
Soon after that, Williams went from trailing 4-2 to not only taking the first set but also leading 4-0 in the second.
By the end, Williams compiled a 13-3 edge in aces, and 35-12 in total winners.
Defending champ Stephens eliminated
First, there were four break points squandered, along with an early chance for the lead.
Next, three more wasted.
Pretty soon, Sloane Stephens' run at a U.S. Open repeat was lost too.
The defending champion was eliminated Tuesday, beaten by Anastasija Sevastova 6-2, 6-3 in the quarter-finals.
"I didn't play the big points well, and you don't win matches when you don't take your opportunities," Stephens said.
Stephens beat Sevastova in the same round last year en route to her first Grand Slam title, but she missed numerous chances to grab an early lead in the rematch and could never get back into the match.
Sevastova, the No. 19 seed from Latvia, will play Williams in her first Grand Slam semifinal.
That's further than it ever appeared Sevastova would get in tennis when she retired in May 2013, her body battered by muscular and back-related injuries. She returned nearly two years later and finally broke through on her third straight appearance in the U.S. Open quarterfinals.
American Sloane Stephens’ run to another U.S. Open title ended following a straight-sets loss to Anastasija Sevastova. (Al Bello/Getty Images)
"It was an amazing journey, this three, four years," she said.
Stephens said she had been battling a cold, but her biggest problem Tuesday might have been her serve. The No. 3 seed was broken five times in the 84-minute match.
"Mentally, physically, I just wasn't connecting," Stephens said. "It just was a really tough day. The heat doesn't make it any more fun."
Stephens, one of the best defenders in the game, squandered all seven break-point chances in the first set, missing out a chance for early momentum during a lengthy third game of the match.
She couldn't convert four chances to break in that game that lasted 18 points, and Sevastova then quickly broke her for a 3-1 lead. Stephens then couldn't convert three more chances in the next game, and never got another in the first set.
Isner ousted
John Isner doubled over and rested his elbows on his knees. He grimaced. He shook his head.
He looked as if he wanted to be anywhere but where he was: Falling further and further behind against Juan Martin del Potro in muggy, energy-robbing heat at the U.S. Open.
Isner's bid to become the first American man in a dozen years to get to the final four at Flushing Meadows ended Tuesday with a 6-7 (5), 6-3, 7-6 (4), 6-2 loss to No. 3 seed del Potro, the Argentine who won the 2009 championship.
The temperature, more than 90 degrees (32 degrees Celsius), made things uncomfortable across the 3 1/2-hour match. So did the humidity, at about 50 per cent. Those kinds of conditions were a problem for Roger Federer when he was upset by 55th-ranked John Millman a night earlier, and Isner had all kinds of trouble, too — certainly more than del Potro did.
Isner walks off the court after his loss to Del Potro. (Al Bello/Getty Images)
Things got so bad around the site that the tournament suspended junior matches for a few hours in the afternoon. The U.S. Tennis Association invoked its new extreme heat policy, which allows men to take a 10-minute break after the third set, but that clearly didn't help Isner, who quickly trailed 3-0 in the fourth.
This has been something of a breakthrough season at age 33 for Isner, including two hard-court titles and a run to his first Grand Slam semifinal, which happened at Wimbledon in July. He followed that up by getting to the quarterfinals in New York for the first time since 2011; no one from the U.S. has made it past this stage at this tournament since Andy Roddick in 2006, three years after he became the country's most recent male champion at any major.
But del Potro presented all sorts of problems.
His serve is almost as imposing as Isner's, while other elements of del Potro's game — returns and, most notably, his thunderous forehand, which often clocks in at more than 161 kph — are superior.
He now will face either defending champion and No. 1 seed Rafael Nadal or No. 9 Dominic Thiem in the semifinals on Friday. Nadal-Thiem was scheduled for later Tuesday night.
If Nadal wins that, he and del Potro would have a third consecutive Grand Slam meeting: del Potro lost to the 17-time major champ in the French Open semifinals and the Wimbledon quarter-finals.
Canadian advancing in junior
Canada's Leylah Fernandez is heading to the third round of the girls' draw at the U.S. Open.
The 15-year-old from Montreal downed Mylene Halemai of France 6-2, 6-2 on Tuesday.
Fernandez won 71 per cent of her points on first serve and broke her opponent six times.
The Canadian reached the semifinals of the French Open girls' draw earlier this year.
Fernandez will face unseeded Taisya Pachkaleva of Russia in the third round at Flushing Meadows.
