Novak Djokovic was made to work harder than he expected for a straight-sets victory over Salvatore Caruso, with Jan-Lennard Struff awaiting in round four of the French Open after outlasting Borna Coric.
Top seed Djokovic triumphed 6-3 6-3 6-2 against qualifier Caruso but was made to sweat on the hottest day at Roland Garros this year. The Serbian will face Struff after the unseeded German dug in to down Coric 4-6 6-1 4-6 7-6 (7-1) 11-9.
Last year's runner-up Dominic Thiem came through a testing encounter against fellow clay-court specialist Pablo Cuevas 6-3 4-6 6-2 7-5, but the going was easier for Gael Monfils and Karen Khachanov, who beat Antoine Hoang 6-3 6-2 6-3 and Martin Klizan 6-1 6-4 6-3 respectively.
Despite an injury scare while beating Yoshihito Nishioka in five sets last time out, Juan Martin del Potro sealed a 6-4 6-4 6-0 victory over Jordan Thompson.
Stefanos Tsitsipas and Stan Wawrinka triumphed in matches held over from Wednesday, while Alexander Zverev once more required all five sets to advance.
"I WAS PLEASANTLY SURPRISED"
Djokovic acknowledged that Caruso caused him problems during the first half of their match and he had to change his approach and up his game in order to close it out in three sets.
"Caruso was very motivated. I thought he stepped into the court having a clear game plan, attacking the ball from both forehand and backhand. He was hitting backhand very, very good, very solid," said Djokovic.
"He actually pleasantly surprised me with his game. I had to change my tactics quite a bit throughout the match. I think midway through the match I kind of stepped it up a little bit. I feel like I took my game to a different level, which then resulted with easier third set.
"It was a straight-set win, but it was tougher than the score indicated."
TSITSIPAS EDGES THROUGH
Tsitsipas had just reeled off three games in succession to draw level in the third set, having won the first two, when bad light forced his match against Filip Krajinovic to be suspended.
Krajinovic made the most of that reprieve by winning a tie-break to force another set, in which Tsitsipas twice had to fight from a break down to take it to another breaker.
The Greek sixth seed then had to save a set point before finally getting over the line. He still managed to get off court before his next opponent Wawrinka, who failed to serve out the third set and had to save five set points before getting over the line in a tie-break against Grigor Dimitrov.
It was Wawrinka's 500th career win and means he has now beaten Dimitrov at every single grand slam.
OLD HABITS DIE HARD FOR ZVEREV
After playing three straight five-set matches before his quarter-final exit at Roland Garros last year, Zverev kicked off his bid for a French Open title this year with yet another against John Millman.
Getting past Mikael Ymer in three in round two seemed to suggest his progress was going to be more serene, but once again he was taken the distance by Dusan Lajovic - as he was in 2018.
The fifth seed has another tough opponent in the last 16 in the shape of Monte Carlo Masters champion Fabio Fognini, who ousted Roberto Bautista Agut to move one match away from a second grand slam quarter-final appearance.