American teenager Taylor Fritz won the biggest match of his career Thursday night, beating second-seeded Steve Johnson 7-6 (5), 7-6 (7) in the second round of the Memphis Open.

The 18-year-old Fritz, the U.S. Open junior winner last year, advanced to the quarterfinals Friday against Germany's Benjamin Becker, a 6-2, 7-6 (6) winner over seventh-seeded John Millman of Australia.

Third-seeded Donald Young was the only seeded player to survive Thursday, topping Marcel Granollers 6-1, 7-6 (2). Ricardes Berankis of Lithuania ousted No. 8 seed Damir Dzumhur of Boznia and Herzegovina 6-3, 6-4.

The victory moved Fritz into his first quarterfinal on the ATP Tour, becoming the first American 18-year-old to reach the quarters of a tour event since Denis Kudla at Newport in 2011.

"It feels amazing," Fritz said. "I played a really great match, and I'm so happy to get the chance."

Fritz was able to capture the match by not losing focus when he was on the ropes as he faced break points. Fritz, ranked 145th in the world, saved nine of 11 break points.

"I thought he played an insane match for him," Johnson said. "It's probably the best he's played on this level by far. I had a lot of chances, but he somehow just won all the big points. It's a tough one definitely for me."

The match, which lasted almost two hours, featured plenty of long rallies as the pair flailed away at shots from the baseline — Johnson changing pace and spin at times on his shots, Fritz using his big shots to counter the strategy.

A backhand down the line off Johnson's serve in the second set tiebreaker gave Fritz the victory over the 29th-ranked player in the world — his first win over a top-30 player.

The night didn't get off to the best start for Fritz as Johnson broke the teenager's serve in the opening game of the match. Fritz said he wasn't necessarily surprised because the two regularly practice together and Johnson routinely breaks him early.

'I just got that out of the way," Fritz said, adding "I told myself I had to start moving better and getting myself into the match."

At that point, it was a matter of the teenager weathering tough situations throughout the match.

"I had a lot of chances," Johnson said, "but it's one of those days where you don't win the big points."