American teenager Coco Gauff is back in the French Open quarterfinals. Twelve months after reaching her first Grand Slam quarterfinal in Paris, Gauff is again one of the last eight players standing thanks to a 6-4, 6-0 win over Elise Mertens.

Gauff, seeded No.18, was down a break twice in the first set against No.31 seed Mertens, but won the last eight games of the match. She wore Mertens down over the course of 82 minutes with world-class defense; Gauff won 51 of the 75 total points of more than five shots in the match.

Mertens, who missed much of the clay-court season before the French Open with an injury, hit 25 unforced errors and only 15 winners. Gauff, conversely, hit 19 winners to 17 unforced errors. She also broke Mertens six times and won 17 of 20 points went she went to net.

"I feel like every match I'm getting better. I think today even though I had some tough moments I was able to tough it out. I really do feel like I'm progressing with each match," Gauff said after the match.

"I definitely feel confident on the court. I feel like [clay] really suits my game. ... The previous tournaments this clay season, I had some good wins but it wasn't really any outstanding results. I feel like it gave me a lot to learn from, and I think I'm taking those tough matches that I lost this season and really learning from them and I guess showing that I'm doing better."

Match management: Gauff's second career win against the Belgian was less complicated than her first: a three-set comeback last year on the grass in Eastbourne from 6-0, 2-0 down.

Even so, six of the 10 games the pair played in the first set stretched past deuce, and Gauff lost serve in two such games to trail 2-1 and 3-2. She responded immediately to the adversity by breaking back straight away, and kept momentum for good after a 57-minute opening set.

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The youngest of three teenagers to reach the last 16, Gauff joins Leylah Fernandez in the quarterfinals. Zheng Qinwen, 19, is the next player up for World No.1 Iga Swiatek, and they'll play their fourth round match on Monday.

Gauff will next face compatriot Sloane Stephens at a major for the second time in the span of a year. Trailing No.23 seed Jil Teichmann with the Swiss serving at 2-0, 40-15, Stephens won 12 games in a row to reach the quarterfinals in Paris for a third time.

The two Americans played last summer in the second round of the US Open, and that match was won by Stephens, 6-4, 6-2.

"I think last time I played her I was super nervous going into the match. Not because it was Sloane. Just because we were on Ashe and it was all-American matchup. I think a lot of people expected a lot from me in that match,"  Gauff said.

"Going in ... [I'm] just going to approach it like any other match. I have to go back and watch that match and see what I can learn from it."

Stat of the day: Stephens has now won 12 games in a row twice this fortnight. She previously trailed No.26 seed Sorana Cirstea in Round 2, 6-3, 2-0.