Richard Gasquet won the battle of the Frenchman in the first round of the Gerry Weber Open to eliminate Gael Monfils in Halle.
It was fifth seed Monfils that claimed the first set but Gasquet, who turned 31 over the weekend, fought back to win 3-6 6-4 6-3 against a compatriot who has struggled on grass down the years.
Second seed Dominic Thiem, who has only Roger Federer ahead of him in the rankings this week, had few issues in advancing beyond Maximilian Marterer in straight sets in the tournament's opening contest.
Thiem was a semi-finalist at the French Open earlier this month before losing to Rafael Nadal and continued his good form on a different surface as he dispatched Marterer 7-5 6-3.
Thiem saved all seven break points he faced while converting two himself.
Dustin Brown, Philipp Kohlschreiber and Andrey Rublev all needed over two hours and three sets to make it through against Vasek Pospisil, Joao Sousa and Albert Ramos-Vinolas respectively.