The bottom half of the men’s draw at the US Open played out in underdog fashion Sunday as Diego Schwartzman, Kevin Anderson and Pablo Carreno Busta moved into the quarterfinals.

The No. 30-seeded Schwartzman Beat No. 16 seed Lucas Pouille 7-6(3), 7-5, 2-6, 6-2 to reach his first Grand Slam quarterfinal.

“All the matches, [the crowd is] helping me a lot,” the 25-year-old Schwartzman said. “In the first round and second round as well, they are helping me a lot. When it’s a tough moment, they are making noise with me, just to be with me in the match. That is helping me a lot. I am really happy for that and thanks to everyone for doing that.”

Schwartzman received treatment on his upper right leg in the third set but showed no ill effect. And at 5-foot-7 he became the shortest Grand Slam quarterfinalist since the Jaime Yzaga at the 1994 US Open.

He will next meet the No. 12 Carreno Busta, who ended the Cinderella run of Canadian qualifier Denis Shapovalov 7-6(2), 7-6(4), 7-6(3).

“It’s going to be really nice for me,” Schwartzman said about playing Carreno Busta. “I am really happy to be in the quarterfinals this year. Even more because Pablo is my friend outside the court. We have a good relationship in the locker room and we have a lot of things outside the tennis life.”

Carreno Busta found himself down early to the 18-year-old Canadian 5-2 in the first, and then saved 3 set points to take the first set. The Spaniard then maintained his level in the second to scratch out another break.

In the third Shapovalov got a last wind going up a break, but it was too late. His run was done.

It was incredible,” said Carreno Busta. “The people was supporting all the time. There is a lot of noise, and you think the people is behind you, but I just tried to be focused on the match. And then at the beginning I was a little bit scared, maybe a little bit nervous.

“But after he broke me, I talk to my coach. I don’t know if he heard me, because there was a lot of noise. But I told to him that I can win the match, but I need to be very aggressive because he plays really good. And I just tried to do it. I continued fighting all the time.

“In the tie-breaks, I just played perfect. I played very aggressive. I served really good. It was very tough, because three hours, three sets, three tie-breaks, but of course it was an amazing victory for me. Now I’m in the quarter-finals again of a Grand Slam, first time here in US Open, and will try to continue.”

Shapovalov, who was off the radar just a few months ago, will move up into the Top 55 after his incredible summer.

“I think I had a lot of chances,” said Shapovalov. “I don’t think I played as well today as I have been these past two weeks, but, I mean, that’s tennis. It’s going to happen.

“I think Pablo played a very great match. He stayed very tough mentally in the big points. He just played three tie-breaks that were better than mine. I was up in the first, up in the third. I definitely had my chances. Very disappointed that I wasn’t able to keep my leads.

“But at the end of the day, it’s tennis. I still have a lot of things to learn. Hopefully I can come back and one day I can make it further here.”

Carreno Busta is into his second straight quarterfinal at a Slam after Paris.

Another winner of an unlikely second-week Slam match-up was No. 28 seed Kevin Anderson defeating unseeded Paolo Lorenzi 6-4, 6-3, 6-7(4), 6-4. The 6-foot-8 Anderson finally lost serve but managed to overcome a break down in the fourth to close out the Italian debutante.

“Obviously I think getting here in this position a couple years ago, it was a very valuable experience in today’s match,” Anderson said. “Obviously at this stage of tournaments, it means a lot. I think just being at that stage previously made me settle a little bit…I feel like I’m playing really good tennis. My body’s healthy. It was a pretty tough loss at the beginning of this year with a few injuries.”

In the quarters Anderson will meet Sam Querrey who destroyed Mischa Zverev 6-2, 6-2, 6-1 in 1 hour, 16 minutes, the shortest completed men’s match of the event this week.

Into his first US Open quarterfinal, Querrey clocked 18 aces with 55 winners and 8 unforced errors. And he also became the top ranked American for a first time, passing John Isner.

Matches scheduled Monday are (1) Rafael Nadal vs. Alexandr Dolgopolov, (3) Roger Federer vs. (33) Philipp Kohlschreiber, (9) David Goffin vs. Andrey Rublev, and (6) Dominik Thiem vs. (24) Juan Martin del Potro.

Federer leads Kohlschreiber 11-0 in their series. Dolgopolov does have two wins over Nadal but Rafa has six.

And del Potro vs Thiem is a rematch from last year.