NEW YORK – The third round begins, and the cool change has arrived.
After scorching temperatures led to a non-record, but still considerable number of retirements, it’s significantly cooler on this first Friday.
On the plus side, the temperature is expected to hold steady in the mid 70s. On the minus side, it will be cloudy all day and we could see our first rain of the tournament.
And it remains, despite the cooler temps, extremely humid.
That won’t affect the play on Arthur Ashe Stadium or the new Louis Armstrong Stadium, which have retractable roofs. But it could impact all the other matches going on around the grounds.
The way the radar looks, though, it seems like Queen’s may be on the outer edge of a pretty significant band of precip, so we might well escape the worst of it.
Lahyani chastised, but on the job
The USTA finally came out with a press release that made sense Friday morning, as it acknowledged that veteran chair umpire Mohamed Lahyani overstepped his job description Thursday during the Nick Kyrgios match.
Lahyani won’t be suspended or penalized. He’ll continue to do his job – and he’s good at his job. But we’re likely to see a chastened version on the courts today.
There’s a big third-round match tonight on the big stadium. Everything else today is a bonus.
There are eight third-round clashes on the men’s side today – third-round encounters that, in theory, have the seeds finally meeting each other.
But only three of them have gone according to form.
On the women’s side. only two feature seed vs. seed: Mertens vs. Strycova, and the all-Williams clash.
Three women’s matches to watch
 Venus Williams (USA) vs.  Serena Williams (USA)
The machinations and calculations involved in upgrading former champion Serena Williams’s seeding at this US Open ended up backfiring.
We don’t know for a fact – these were top-secret deliberations – that they gave Williams the No. 17 seed to avoid bumping her big sister Venus out of the top 16.
But the way the draw shook out, they end up meeting in the third round.
Had Serena Williams maintained her original seeding of No. 26, she would have faced one of the top eight seeds – the top two of which are already gone after two rounds).
Instead, she faces her sister for the 30th time in their careers.
Serena holds a 17-12 edge.
They last met at Indian Wells this year, where Serena was returning to action for the first time in singles since her maternity leave. Venus won that one. Before that, they met in the 2017 Australian Open final – the last tournament before Serena’s leave.
As Venus jokes, it was “two against one” in that one, won by Serena 6-4, 6-4 with baby Olympia already more than a twinkle in father Alexis Ohanian’s eye.
2.  Sloane Stephens (USA) vs. [WC] Victoria Azarenka (BLR)
Azarenka has looked very good through her first two matches. She dropped just three games in rolling over No. 25 seed Daria Gavrilova in the second round.
Stephens, the reigning US Open women’s singles champion, had to come back from a set down to prevail over qualifier Anhelina Kalinina of Ukraine in the second round.
On any other day, this would be the spotlight women’s match.
But it may well still be a very good one. Azarenka still holds a 3-2 edge. But she had the misfortune of running into Stephens at both Indian Wells and Miami earlier this year. And Stephens won both of those.
3.  Ashleigh Barty (AUS) vs. [Q] Karolina Muchova (CZE)
Muchova caused a pretty major surprise late Wednesday night (early Thursday morning) as she took down No. 12 seed Garbiñe Muguruza of Spain.
Muguruza because increasingly agitated as that match went on. Muchova, ranked just outside the top 200 coming in, became increasingly at ease after a nervy start to the biggest match of her young career.
The matchup with Barty will be a very different one. And it should be one tennis purists will really enjoy.
Barty is one of the few higher-ranked players on the WTA Tour with a genuinely varied game, full of imagination and with a willingness to hit all the shots and come to the net on a regular basis.
Muchova has similar skills and mindset, even if her pro game is still in its relative infancy.
They get the Grandstand court, which is far less intimidating than cavernous Arthur Ashe Stadium.
For Barty, getting a qualifier in the third round is a great break. For Muchova, the question will be whether she’s able to put aside her career win and keep her head down and her mind uncluttered for her next assignment.
Three men’s matches to watch
The Slam star power is definitely on the women’s side in Friday’s schedule. But there remain some compelling men’s matchups well worth a look – with a distinctly Canadian flavor.
1.  Milos Raonic (CAN) vs. [WC] Stan Wawrinka (SUI)
The former US Open champion Wawrinka needed a wild card to get in this year, as he makes his way back from two knee surgeries.
He’s back in the top 100 now, so that won’t be an issue going forward. But over the last few weeks, his level has been far closer to the top-five performer he was for several years.
As for Raonic, also beset by injuries if not of the same severity, he’s also a former top-five player. And a Grand Slam finalist at Wimbledon two years ago.
Here in New York without coach Goran Ivanisevic, whose wife is expecting a baby, he was better in his second round than he was in his first round. And his serve is working.
Wawrinka holds a 4-1 lead in their head-to-head. Raonic won the last one – a five-setter in the fourth round of the 2016 Australian Open. But that was more than 2 1/2 years ago; a lot of water under the bridge since then.
2.  Juan Martin del Potro (ARG) vs.  Fernando Verdasco (ESP)
Verdasco pulled off a tough one against Andy Murray in the second round. And he saved some energy when doubles partner Vasek Pospisil, who pulled up a little broken the day after his night-match loss to Rafael Nadal, begged off the doubles.
While Federer, Nadal and Djokovic are getting all the attention – with the potential quarterfinal clash between the Swiss and the Serb already highly anticipated – del Potro is definitely under the radar.
It has been nine years since he won his first and, so far, only Grand Slam title here.
Del Potro is 4-1 against Verdasco, with their two best battles coming on very fast indoor hard courts. The courts at the US Open this year are … not that fast.
3.  Kevin Anderson (RSA) vs.  Denis Shapovalov (CAN)
We’ll see what the 19-year-old Canadian has left, after an emotional win over his “brother” Félix Auger-Aliassime in the first round, and a nerve-tinged marathon over veteran Italian Andreas Seppi in the second round.
Shapovalov has burned a lot of physical and mental energy in getting this far. But on the plus side, he’s at the tail end of this summer period where he had to defend both a Masters 1000 semifinal, and a Grand Slam fourth round on the rankings tally.
He’s already largely done that, mitigating any potential drop in the rankings by at least getting credible results both in Canada and in New York.
Against Anderson, the 2017 US Open finalist he’s meeting for the first time, he can at least enjoy shorter points. And on a cooler day. On the downside, Anderson’s big serve will test the young Canadian’s inconsistent return game.
The big South African survived a five-setter of his own in the first round, against American Ryan Harrison.