Dubai - Lucas Pouille found his fitness as he won a re-run of the weekend Marseille final, beating Karen Khachanov 6-4, 3-6, 6-3 on Wednesday at the Dubai Championships.
The Frenchman was the only player from his nation to win on the day from three on court.
Benoit Paire lost 6-1, 6-4 to Borna Coric while Pierre-Hugues Herbert fell to Spanish third seed Roberto Bautista Agut, 6-4, 6-7 (2/7), 6-1.
Bautista and Coric will meet in the quarter-finals.
Japan's eighth seed Yuichi Sugita beat German Jan-Lennard Struff 7-6 (7/4), 6-4 and will face Pouille in the last eight.
On Sunday, Khachanov edged Pouille in the third set in Marseille, but the Frenchman struck back at the Aviation Club in Dubai.
"In the Marseille final, he won just three points more than me ," Pouille said. "I knew it was very close. I had to play some good tennis. "
We were both I think a little bit tired. I'm just very happy that I g ot my revenge today. "
Pouille, who also won the Montpellier title this month, is pleased with his current form.
"As long as you win, you get some confidence. I prefer to win a lot of matches, play a lot.
"I'm very happy with this month of February so far."
Paire's racquet disintegrated in the second game against Borna Coric but it wasn't the only thing to fall apart as he lost in 63 minutes, serving seven double-faults and dropping serve five times.
Bautista needed almost two and a half hours to advance as Herbert forced a third set tiebreaker.
"I had to fight so hard, it was tough to feel good on the court today," said Bautista, a Spaniard ranked number 23 in the world. "We had a lot of wind, it was not easy to play."
Russian Evgeny Donskoy, who upset Roger Federer here a year ago in the second round, hammered fourth seed Damir Dzumhur 6-1, 6-1.