British number three Aljaz Bedene battled hard against Jiri Vesely but he eventually succumbed to defeat in the second round of the French Open.
Bedene, who has recently admitted he's considering switching back to representing Slovenia, looked off the pace for the first two sets.
Zverev and Tsitsipas both suffer surprise defeats
However he fought back really well in the third as he finally got his first break and ensured that he wouldn't be beaten in straight sets.
Vesely broke back again in the fourth but Bedene clung on at deuce when his opponent was serving for the match.
It takes the British representation in the men's singles draw to just two with Andy Murray and Kyle Edmund both in action on Thursday.
Speaking afterwards Bedene said "I fought really well and I'm proud of that but disappointed to lose, especially after I thought I was better in the fourth set,
"I have to learn from it, especially when those first two sets weren't great.
"Then I played well and started to show myself that if I can play my game. I can beat those guys."
He also addressed those comments about possibly switching back to Slovenia, seeking to clarify said comments.
"I really want to play for Great Britain and I'm still hoping," Bedene said.
"I haven't really thought anything outside of that."
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