Prior to facing his countryman in Friday night’s US Open semifinal, Swiss world No. 4 Stanislas Wawrinka spoke to reporters about closing the gap against former world No. 1 Roger Federer.

“I think the past three years, for sure, I get closer from him,” Wawrinka said in his press conference following a straight-sets win over Kevin Anderson of South Africa in the quarterfinals. “My level improved a lot. I’m playing better tennis. …[Friday] is going to be a big challenge. I think I’m ready.”

Instead, Federer improved his head-to-head against his compatriot to 17-3 with an emphatic 6-4, 6-3, 6-1 victory under the lights on Arthur Ashe Stadium Court to advance to his first US Open final since 2009 without dropping a set. All three of Wawrinka’s wins against his Davis Cup teammate have come on clay, the most recent being a straight-sets win en route to the French Open title in May.

Federer will face top-ranked Novak Djokovic, who routed defending champion Marin Cilic in three sets earlier Friday, for the 42nd time in Sunday’s championship match. The all-time record holder for men’s singles Grand Slam titles (17), Federer is looking for his first since winning Wimbledon in 2012. Djokovic, who has already won this year’s Australian Open and Wimbledon – the latter over Federer in four sets –is going for his 10th.

It’s hard to predict Sunday’s outcome, though recent history points to the current world No. 1 – Djokovic, who will be making his fourth Grand Slam final appearance of 2015, has won three of the last four matches between the two. But it is Federer who leads the head-to-head, 21-20, and who prevailed in straights sets the last time they met, in Cincinnati on hard courts last month.

“I think [when Novak and I play] it’s just a straight shootout, and I think that’s the cool thing about our rivalry,” Federer said following Friday’s win. “It’s very athletic. We both can handle each other’s – whatever we present to one another, and I think our matches, it’s very even.”

As he’s been all tournament, Federer was dominant on serve Friday. He made 65 percent of his first serves and won 63 percent of the points on his second. He also converted on 5 of 11 break point chances while Wawrinka was 0 for 4. It was a clean match off the ground for Federer as well as he blasted 29 winners to only unforced 17 errors. Wawrinka racked up 30 unforced errors to 25 winners.

While Wawrinka admitted Friday night was not his best performance, especially on serve – only 49 percent first serves in – he was quick to praise Federer’s high level.

“He’s moving really well, for sure,” Wawrinka said of his good friend. “He’s reading well the game, and so he’s trying really to stay on the line, not to go back. Stay really aggressive. He’s serving really well, also. He’s serving better than I’ve ever seen him serve.”

Follow me on Twitter @jen_beekman

Jennifer Beekman

Spark Sports Tennis/US Women’s Soccer Analyst