US Open: Keys crushes Vandeweghe as Stephens comes out on top in roller-coaster match against Venus to reach final

'It still doesn't feel real, I'm shaking,' says Keys after 6-1, 6-2 victory to set up first all-American showdown championship match since 2002

Sloane Stephens, right, shakes hands with Venus Williams after defeating her fellow American to reach the US Open final. Mike Segar / Reuters

A ruthless Madison Keys crushed CoCo Vandeweghe 6-1, 6-2 on Thursday setting the stage for an all-American US Open final that will see a new grand slam champion crowned.

Keys' opponent in Saturday's final will be world No 83 Sloane Stephens, who beat ninth seed Venus Williams 6-1, 0-6, 7-5 in an earlier roller-coaster clash.

It will be the first time two American women have played for the title since 2002 when Venus lost 6-4, 6-3 to her younger sister Serena Williams.

"It still doesn't feel real, I'm shaking," smiled Keys. "There are a lot of things in my head right now so I'm struggling to come up with the words but I think I played really well.

"I had to rise to the occasion and I'm just happy to be in the final.

"Sloane is a new person right now, I think she is loving being out on the court again and she's obviously playing really well."

The final shapes up as an intriguing and unexpected one featuring two players who missed the start of the year as they recovered from injuries.

Keys, who was absent from the first two months recovering from wrist surgery, delivered an old fashion thrashing as she needed just 66 minutes to beat Vandeweghe, who also lost in the Australian Open semi-finals.

Keys came out swinging against the fellow power-hitter and broke Vandeweghe twice as she stormed into a 5-0 lead in a one-sided opening set that took only 23 minutes.

Keys continued to hammer away in the second set and the 22-year-old American broke in the third game to ensure her momentum continued.

The only alarming moment came when Keys called for a medical time out while leading 6-1, 4-1 and she walked off the Arthur Ashes Stadium court for treatment.

The 15th seed returned with her right thigh heavily taped but it had no affect on her dominance as she held serve and finished off a shell-shocked Vandeweghe in her next service game with an ace on the first match point.

"I definitely was starting to feel it and I was afraid if I went too far into a corner then something more serious could happen so I felt I needed to get it worked on sooner rather than later," Keys said.

"I feel great right now, I don't think I could feel better than I do now."

The friends and Fed Cup teammates will meet Saturday at Arthur Ashe Stadium in the biggest match of either's career for a top prize of US$3.7 million (Dh14m).

"I've known her for a long time. She's one of my closest friends on tour," Stephens said. "I love her to death. And it's not easy playing a friend."

Stephens, who was wearing a walking boot in June and ranked 957th in July, has won 14 of her past 16 matches, with semi-final runs at Toronto and Cincinnati.

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"I have no words to describe what I'm feeling, what it took to get here, the journey I've been on," Stephens said.

"It's incredible. I don't know how I got here. Your guess is as good as mine. Just hard work. That's it."

Stephens beat Keys in the second round at Miami in 2015 in their only career meeting.

"Sloane is a new person right now," Keys said. "She's so excited to be out on the court again. I'm excited we get to play each other in the US Open final."

Stephens needed a thrilling break at love in the penultimate game and closing hold of serve to deny two-time champion Williams her first US Open final in 15 years.

"I just worked my tail off and tried to run every ball down and here we are," Stephens said. "It required a lot of fight and a lot of grit."

Now 83rd, Stephens is the lowest-ranked grand slam finalist since unranked Justine Henin at the 2010 Australian Open and the lowest at the US Open since unranked Kim Clijsters won the 2009 title.

Stephens, who beat Williams in the first round of the 2015 French Open in their only prior meeting, will jump into the world top 25 next week with the victory.

US ninth seed Williams could not overcome 51 unforced errors that doomed her bid to become the oldest women's singles finalist in US Open history at age 37.

"It was definitely well competed," Williams said. "In the end she won more points than I did and that's what it added up to.

"Just made so many errors at the end there ... I wasn't playing well. Just wasn't playing well."

Williams will return to the top five in Monday's world rankings for the first time since 2011, the year she was diagnosed with strength-sapping Sjogren's Syndrome.

Stephens, 24, is 4-0 in WTA finals, having won titles in 2015 at Washington and last year in Auckland, Acapulco and Charleston.

On Friday, the men return to Arthur Ashe Stadium with 15-time grand slam champion Rafael Nadal, the world No 1, seeking his fourth trip to the New York finals against 2009 US Open champion Juan Martin del Potro, the 24th seed from Argentina.

South African Kevin Anderson and Spain's Pablo Carreno Busta meet in the other semi-final.