Casper Ruud’s hopes of advancing to a third successive French Open final ended in a four-set defeat by Alexander Zverev on Friday as the Norwegian said he was laid low by a stomach bug.

The two-time Roland Garros runner-up won the first set convincingly against Zverev before the German fourth seed fought back against an ailing Ruud to win 2-6, 6-2, 6-4, 6-2. “It was a little bit unfortunate. I started well. Towards the middle, end of the first set, I started feeling some discomfort, an ache in my stomach. So I wasn’t able to keep the intensity and the energy level up,” said Ruud.