NEW YORK, NY, USA -- The Summer of Sloane has a Slam.

In a tour de force performance, Sloane Stephens overwhelmed fellow American and No.15 seed Madison Keys, 6-3, 6-0, to win her first Grand Slam title at the 2017 US Open, on Saturday afternoon in Arthur Ashe Stadium.

"It hasn't sunk in yet," Stephens said in her post-match press conference, "but hopefully in a little while once I, like, am able to lay down and relax and think about it, I'll realize that I really am the US Open champion."

Stephens put on a calm, pristine display, with 10 winners and only six unforced errors. Keys' 30 unforced errors negated her 18 winners, and she was often frustrated by Stephens' superb ability to extend the points.

"I made six unforced errors in the whole match?" exclaimed Stephens afterwards. "I don't think that's ever happened to me before. That's a stat. Snaps for me," she continued, snapping her fingers.

Stephens also was never broken in the 61-minute match, as Keys was 0-for-3 on break point opportunities, which all came during a single game late in the match.

With the title, Stephens moves up to World No.17 -- a far cry from her oft-discussed No.975 ranking to start the summer. Stephens also improves to 5-0 in WTA finals.

"Before the match, I was super nervous," Stephens said. "I just tried to stay calm and keep my composure and run every ball down. That was it. Super simple."

The match started with both players testing each other's strengths: Stephens' movement and inventiveness, and Keys' power on the serve and the forehand. Both were tentative initially, during the first Grand Slam championship match for either of them.

It was Stephens' steadiness which caused Keys to cede serve first, throwing in three unforced errors at 2-2 to give Stephens the initial lead. Stephens smoothly held onto her serve for the next two games, forcing Keys to up the ante if she wanted to make it back into the set.

Keys continued to play aggressively, but, more often than not, her shots failed to stay within the lines. Stephens claimed her first set point at 5-3 when she hit a backhand square on the baseline, but an unforced error -- only her second of the match up to that point -- gave it away.

But a backhand error by Keys later in the game gave Stephens a second shot to break for the set -- and a second consecutive backhand error handed the 6-3 set to the unseeded player.

There were almost no issues for Stephens in the second set. Keys tried to change things up and started pressing at the net, coming in more, but Stephens had the answers, breaking for a 2-0 lead in a game where she hit two wonderful passing shots -- one each off the forehand and backhand.

Keys still could not quell her unforced errors, and gave Stephens another break for 4-0, when she double faulted down break point.

The only time Stephens was troubled in the match was when she was serving at 4-0 and quickly went down triple break point -- Keys' very first break points of the match. But a backhand winner, a forehand winner, and a volley winner after an outstanding rally put her back at deuce, and she held from there for 5-0.

Keys, now deflated, continued to try to find the winners that had propelled her run to the final, but it was too late, and Stephens converted her third match point to complete the second set wipeout. Unbelievably, Stephens won the final eight games to close out the match and clinch the first Grand Slam championship of her career.

"I was just fortunate enough to hold it together a little bit longer, and I just went out and competed and ran after every ball," said Stephens. "That's all I focused on."

Thus, the Summer of Sloane comes to its conclusion with the grandest ending imaginable. "When I had surgery, I was not thinking that I would be anywhere near a US Open title," the champion admitted.

"I was thinking about all the wrong things," Stephens continued. "Once I kind of let that go and just realized that whatever is meant to be is going to be, that I worked hard to get here and, you know, that's that, then I think a lot of that stress was relieved and I was able to just play free and run and compete and just get out there and get after it every match."

"I mean, there's no words to describe how I got here, the process it took or anything like that, because if you told someone this story, they'd be, like, 'That's insane.'"