Martin started from fifth on the grid at Le Mans but leaped up to second on the opening lap, before taking the lead from Francesco Bagnaia on the fourth tour.
Immediately, the Pramac Ducati rider opened up a lead of eight tenths before taking the chequered flag 1.8s clear of the field.
It marked his first sprint win of the season and his first victory of any kind since the 2021 Styrian Grand Prix.
Martin thought the sprint “would be a day to prepare” for the grand prix because of how uncomfortable he felt on his GP23 and wasn’t anticipating a victory charge.
“I didn’t expect to fight… well, to fight [for the podium] yes, but not for the win,” Martin revealed.
“Today I thought it was a day to prepare for tomorrow’s race because yesterday and this morning I didn’t feel great.
“I felt like I didn’t have the bike to fight for it, but with this temperature I felt good.
“I feel like something has unblocked in my head. It’s only a sprint race, but it’s been a long time since my last victory.
Source: Autosport