Williams was at her imperious best in defeating her Latvian opponent, taking only 66 minutes to dispatch her 6-3 6-0.
Williams will meet Naomi Osaka of Japan, the winner of Thursday’s other semifinal on Saturday.
Osaka won Thursday’s late match against American Madison Keys 6-2 6-4 to advance to her first grand slam final.
Keys refused to give up, and early in the second set, after a dispiriting end to the first set, looked to get back in. On Osaka’s first service in the second set she fought hard for the break in a 22-point, six break-point game.
The partisan crowd tried to buoy the American as she gained in confidence but it was a tough ask as the young Japanese methodically brought her advances back down to earth.
Dominant display
Earlier in the evening Sevastova broke Williams’ serve early in the match, but once the American all-time great found her rhythm it was clear that there was only going to be one outcome.
While she was dominant with her powerful groundstrokes, Williams also showed her strength at the net, winning 24 of 28 points when coming forward.
It is the six-time winner’s first US Open final in four years, including a missed tournament last year.
Should she be successful on Saturday, Williams would equal Margaret Court’s all-time record of 24 major wins. The Australian was a dominant force in women’s tennis throughout the 1960s and 70s.
Historic meeting
As well as Williams’ chance to equal the all-time women’s record for grand slam titles, Saturday will see the first-ever Japanese woman grand slam finalist when Osaka takes the court. At 20, she will be the youngest women’s US Open finalist since Caroline Wozniacki in 2009.
Osaka — who has had made great strides in 2018, winning Indian Wells in March — said the opportunity to meet the US legend in the final was a powerful motivator.
“This is going to sound really bad but I was thinking, ‘I really want to play Serena’,” she said, adding when asked why, “because she’s Serena! What do you mean?”
Osaka said that beating Keys for the first time felt “really weird.”
“I’ve never beaten Madison. I was just glad to get through this match, she’s such a good player.”
She thanked the crowd and had a special message for her mother, who was watching from the stands at Arthur Ashe.
“Mom, I did it! I love you! Thank you.”
Asked if she had a message to her final opponent, she repeated “I love you” to laughs around the stadium.
“I love everybody! Thank you!”
Comeback
“It’s honestly really incredible,” said Williams. “A year ago I was fighting for literally my life at the hospital after I had the baby. Every day I step on this court I’m so grateful that I have an opportunity to play this sport.
“No matter what happens in any match, semis, finals, I just feel like I’ve already won.”
Should she triumph on Saturday, she could find herself promoted to just outside the top 10, the latest step in a remarkable comeback. Even if she falls at the final hurdle, she will advance to at least 16th in the WTA’s latest rankings, released Monday.
In her journey to the final, Williams knocked out Czech Karolina Pliskova, who enjoyed a brief spell as world No.1 in 2017. She also bettered her sister, Venus — seeded one higher than Serena at 16 — the unseeded Estonian Kaia Kanepi, Carina Witthoeft of Germany, and Poland’s Magda Linette.
Source : Nbcnewyork
