The Frenchman’s third career Vuelta victory now ties him on time with Jonas Vingegaard, who managed to preserve the red leader’s jersey.
Pedersen went into the stage as the overwhelming favourite, but ran out of strength in the final sprint as Gaudu recorded his first stage win in a Grand Tour in five years.
“I was thinking in the bus this morning it was more for Pedersen, but (Stefan) Küng said to me this morning I have a punch and I can win today,” a delighted Gaudu said in the TV interview after the finish.
“The team is doing a very, very, very good job. They keep us on the first position all day. So I'm very happy. I'm very, very proud to win for me, for the team. This is, I think, the best start to the Vuelta we could get."
“When I see Pedersen launching the sprint at 200-250 metres, I disconnect totally on the last corner and push all my limits to the finish line,” he added.
Jonas Vingegaard remains general classification race leader and will start tomorrow’s stage in the red jersey. Gaudu is now second in the general classification, while Ciccone is third, and Bernal fourth. Thomas Pidcock completes the GC top five.
Tuesday’s stage 4 of Vuelta a Espana 2025 will see the riders in the peloton complete 206.7-kilometer from Susa, in northwestern Italy, to Voiron in southern France.