The front pack was whittled down to three riders before Mas proved too strong for Victor Lafay (Cofidis) and Elie Gesbert (Arkea-Samsic) in the finale. With 200m left, Mas darted ahead of the rivals to take victory and seize control of the race.
Miles Scotson (Groupama-FDJ), leading the race after the first two stages, slipped outside the overall top 10.
“This victory really feels great – my first win with these colors! I’m super proud of how the team has worked today; they all really were on top of their game today, just like over the whole Volta a la Comunitat Valenciana, always trying to give their best. We’ve been able to finish this off and it’s been in great part because of them,” Mas said.
The 14.3km stage 4 time trial is as flat a route as the region can offer with a slight incline at 9km, on an otherwise short and flat stage.