Stage four marked the first day of racing in Italy following three days in Albania and Monday’s rest day.
Spain’s Francisco Munoz spent 140km off the front after making an early solo breakaway and led by more than four minutes before being reeled back in with 55km to go in a race controlled by the sprint teams.
Race leader Pedersen was forced to chase back to catch the peloton after being caught up in a crash, alongside team-mate Soren Kragh Andersen, with 22km to go.
On a Lecce circuit full of bottleneck turns, van Uden’s Picnic PostNL team pinched the lead from Alpecin-Deceuninck, riding for Kaden Groves, in the final kilometre, before the 23-year-old opened up a long sprint to victory.
“I didn’t do it alone. I did it with the whole team,” van Uden said. “I didn’t have to take any wind until 200m to go.
“I know I have a good long sprint, so I went for it and hoped for the best.”
In the general classification, Isaac del Toro leapfrogged Juan Ayuso into fifth place. Great Britain’s Max Poole remains seventh, 33 seconds behind Pedersen.
Wednesday’s stage five is a 151km hilly stage from Ceglie Messapica to Matera.
