Dubai - Novak Djokovic won his 16th match of an undefeated season, hammering Russia's Karen Khachanov 6-2, 6-2 on Thursday for a place in the Dubai Championships semi-finals.
The top seed also tightened his grip on the world number one ranking in the face of competition at this week's Acapulco event from second-ranked rival Rafael Nadal.
"Karen made a lot of unforced errors, which obviously made my life easier especially in the first set to go up 5-1, two breaks.
The two-hour and 23-minute duel, which allowed Greek Tsitsipas to claim a seventh successive win, set the day's programme at the Aviation Club back by more than an 90 minutes.
"It was tough, I just hung in at the end and got through," unseeded Evans said.
"I was struggling with my return today, I don't know what was wrong with it," Tsitsipas said.
Tsitsipas is defending his runners-up points from last year when he lost the final to Roger Federer.
"Semi-finals in any tournament on the ATP Tour is great," he said.