The Canadian Argos-Shimano rider held off competition from Frenchmen Samuel Dumoulin (Ag2R La Mondiale) and Stephane Poulhies (Cofidis) to lead the peloton into Lleida after a 157km ride from Rialp.
Martin kept the leader's jersey and extended his lead over Joaquim Rodriguez to 14 seconds after picking up a bonus second for coming third at the intermediate sprint.
The stage's largely downhill profile - save for a category two climb at Port d'Ager - made for a bunch finish and little change in the general classification.
Olivier Kaisen (Lotto) and Tristan Valentin (Cofidis) mounted a two-man breakaway after 50km but their lead stalled at four minutes and the peloton reeled them in 15km from home.
Marcus Burghardt tried to break clear 2km from home, but his attack was quickly snuffed out. Parisien timed his late surge to perfection, hitting the front with less than 50 metres to go.
A delighted Parisien said: I still can’t believe that I won today. This is the biggest win of my career. But what made it even better was the amazing teamwork. Today we executed our plan perfectly.
"Yesterday we studied the final 3km for a long time. Using the team’s innovative new race course analysis system, we were able to see exactly what would happen in the final 3km, and we made a plan for it. It was important that we be at the front with 3km to go, and Patrick Gretsch brought us to the front right on schedule. After that it was up to Georg Preidler and Albert Timmer to keep the speed high. The guys went 65km an hour.
"From our reconnaissance last night we knew it would be crucial to go through the last corner in the top three. We did, and Albert led me out perfectly in the final meters. Everybody followed the plan and I finished it. It was unbelievably strong teamwork, and I am very proud to win my first bunch sprint ever."
Saturday's penultimate stage sees the race head back into the mountains, with the category one Alt de Prades and category two Alt de Lilla likely to have a decisive impact on the general classification ahead of a flat final stage on Sunday.
Tour de France winner Bradley Wiggins lies fourth overall, 46 seconds behind Martin and primed to make an assault on the leader.