Jannik Sinner dispensed revenge after four consecutive losses to Stefanos Tsitsipas, with the Italian posting a 6-4, 6-3 second-round upset of the ATP Rotterdam top seed on Thursday.
The 14th-ranked Sinner came to the court at the Ahoy stadium with a 1-5 record in the series with the world No. 3 Greek, losing finalist last month at the Australian Open.
Sinner had lost their last meeting in the Melbourne fourth round, a five-set thriller.
Defeat in 81 minutes was only the second loss of the season for Tsitsipas, who leads the ATP with 13 match wins this season.
Sinner notched his first career defeat of a Top 3 player – biggest of his career. He produced 20 winners and a dozen unforced errors. Tsitsipas had 23 unforced and just eight winners.
“It means a lot obviously,” Sinner said. “There was a lot of work behind. I’m very happy. I played some good tennis.
“I was very focussed today. Hopefully I can keep it going but for sure,
“Stef is an incredible player. I have a lot of respect for him. He played incredible tennis this year already.
“I was looking forward to this match to be honest, after my win yesterday already. So I’m very happy about my performance today.”
The Italian sent a stinging backhand winner down the line on the first of three match points to wrap up victory with minimal fuss and now faces former tournament champion Stan Wawrinka in the Friday quarter-finals.
Sinner, winner of the title last weekend at Montpellier, broke three of four times and never faced a break point against his own serve.