Dominic Thiem, Grigor Dimitrov, and Alexander Zverev all had to come from a set down to win their second-round matches at the Monte Carlo Masters on Tuesday.
Austrian fifth-seed Thiem saved match point in a gripping 5-7 7-5 7-5 win over Russian youngster Andrey Rublev, while Dimitrov beat Pierre-Hugues Herbert 3-6 6-2 6-4, and Zverev edged out Gilles Muller 4-6 6-3 6-2.
"I had to fight from the first to the last point, which of course I did well. But I was also lucky at the end when he had a match point and missed a forehand by 10 centimetres or so," said Thiem. "I was 10 centimetres from being out of the tournament."
Thiem, 24, could also have to face defending champion Rafael Nadal in the quarter-finals if he can get past Novak Djokovic or the in-form Borna Coric on Thursday.
"It's a horrible draw for sure, from the first round on," conceded Thiem.
Dimitrov stepped up his game midway through the second set, reeling off five consecutive games to level the match.
The 26-year-old, who won the Cincinnati Masters and the ATP Tour Finals last season, threw away an early break in the third set, but quickly refocused to finish off the spirited Herbert.
"I was just a little bit rusty, I haven't played a match for almost three weeks," Dimitrov said. "All I (could) do was just fight and win. How doesn't really matter."
Germany's Zverev recovered from a slow start to claim a convincing win over Muller of Luxembourg in the end.
Earlier, French No 1 Lucas Pouille blew a one-set lead as he was dumped out by German Mischa Zverev in a third-set tie-break and Belgium sixth seed David Goffin proved too good for Greek youngster Stefanos Tsitsipas 7-6 (7-4) 7-5 to reach the last 16 for the third year in a row.
Coverage of the ATP Monte Carlo Rolex Masters gets under way from 10am on Sky Sports Arena every day this week.
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