Sloane Stephens dug in, stepped up, and took it from Venus Williams

Thursday night's US Open semifinal between Sloane Stephens and Venus Williams was a wrecking ball of a match. It swung one way, careened violently in the other direction, and then knocked the damn house down. When the dust settled, only Stephens was left standing amid the rubble.

After two sets that were completely lopsided in each direction and lasted just 54 minutes combined, they went to a third, to decide whether Stephens would make her first-ever Slam final or Venus would play her first US Open championship match in 15 years.

On paper, Venus seemed to have the edge. She had the experience, having won 16 major semifinal matches in her career, including two already in 2017. She had the momentum, having just bageled Stephens in the second set. And she had the benefit of being match tough, having played through a full season's worth of on-court challenges while Stephens had only been back on tour - after a yearlong layoff due to foot surgery - for two months.

Stephens, though. Stephens had her legs. Tramline to tramline, baseline to net, she darted around the court and sent back just about everything Venus threw at her. She ran down drop shots, dug would-be winners out of the corners, and extended point after point. She forced Venus to shrink her margins, and go for broke. She made Venus' forays to the net a living nightmare, making her hit either awkward low volleys or multiple overheads in a row. Nearly every Venus approach went disastrously, especially in the third set, when she won just five of 15 points at net.

For all that, though, Venus' offensive firepower - her huge bail-out first serves and screaming inside-out forehands - kept her in the match, and, ultimately, put Stephens up against it. After nine exhausting, mesmerizing games in the final set, which featured four breaks of serve and just one hold that didn't require a break-point save, Stephens got up from her chair, trailing 5-4, and served to stay in the tournament.

The quality of tennis in the decider had been high, but there were wobbles from both players. Venus had dumped overheads and sitting forehands into net, and hit some nervy groundstrokes that barely cleared the tape. Stephens had gotten noticeably tight on her serve, at one point rolling in a 62-mph pancake that Venus crushed back for a break-clinching winner. It was fair to wonder how Stephens' nerves would hold up, especially after Venus worked her 4-5 service game to 30-all to come within two points of the final.

That's when the two played a heart-stopping, face-numbing point - masterful from both, really - that swung everything. It ended when Venus, who'd gotten herself well ahead in the point with a flat cross-court backhand out wide, hit behind Stephens with a slice approach shot deep into the ad court.

Maybe it was a touch too cute, and Venus should've just hit into the open court. But that's what great defensive tennis will do to you; it forces you to get weird and creative; it forces you to overthink. And regardless, it's not like the play didn't work. She succeeded in wrong-footing Stephens, who had to adjust and make a play on the ball once it was already behind her. Stephens just happened to come up with one of the biggest shots of her life, reaching back to hit a perfect backhand pass up the line.

"That was good, huh?" Stephens said after the match.

"I think that really gave me some momentum and really pumped me up."

No kidding. That was the first of seven straight points Stephens won, most of them in equally majestic fashion.

She held on the following point with an unreturned first serve right down the T. On the first point of the following game, she hit a running backhand lob, returned Venus' smash, sprinted forward to reach the ensuing volley, and lifted another lob over Venus' head, sticking it square on the baseline. The point after that, she caught up to a net-cord ball that had flopped into the deuce-court doubles alley, and chipped it back with a ridiculously angled forehand dropper.

From there, the ball started exploding off her racket, and the rest was academic. She broke Venus to love, then stepped to the line and calmly, confidently served it out.

"I knew that at some point I'd have an opportunity," Stephens said. "It was whether I decided to step up and take it or not (that) was going to be the deciding factor. I think I did that extremely well at the end of the third set."

We've known Stephens has elite tools since she burst onto the scene as a teenager, showcasing her devastating combination of power and speed, and memorably beating Venus' younger sister to reach the Australian Open quarterfinals in 2013. But in the intervening years, when she's struggled with injuries and inconsistency, she's learned she has a lot more than that.

"That I'm a real fighter," she said. "That I have a lot of grit. Surprising.

"Like, to myself, I don't give up. I'm not just going to give it to someone. I'm not just going to let them take it from me. I'm going to make sure I give everything that I have, and I leave everything on the court at all times, no matter what."

Venus Williams isn't in the habit of rolling over or leaving anything in the tank, either. In this match, she bounced back from a disastrous first set to win an even more dominant second. She twice fought back from being a break down in the third. She picked herself up off the mat time and again. She fought for every point, every ball, every inch. She didn't give Stephens anything. Stephens had to step up, and take it.

"I played aggressively, and played the best point I could," Venus said. "And then she played a little better."