Holder Stefanos Tsitsipas moved into the Monte Carlo Masters quarter finals with a 7-5, 7-6 (1) victory over Laslo Djere on Thursday while fourth seed Casper Ruud was knocked out in straight sets by Grigor Dimitrov.

Tsitsipas broke only once in a match where break points were in short supply but the Greek third seed pounced when it mattered most at the end of both sets to seal victory.

The opening set went with serve but Djere was nearly broken when he was down 5-4 after he made three double faults. Djere held on but Tsitsipas switched gears and broke him in his next service game when the Serbian fired wide on set point.

The second set was nearly identical to the first with just one break point between the two. This time Djere forced a tie-break, but Tsitsipas was unstoppable as he took the first five points before sealing the match with a forehand winner.

“I really had to work hard for this win,” Tsitsipas said in an on-court interview.

Earlier, Norwegian Ruud became the tournament’s latest high-profile casualty as he went down 6-3, 7-5 to Bulgarian Dimitrov, who moved into the quarter finals for a fourth time.