Hansen closed with a 3-under 69 to end at 19-under-par 269. He was joined there by Erik Compton (67), John Mallinger (69) and Jeff Quinney (67).
Quinney, the 2000 U.S. Amateur champion, played in the penultimate group and was the first in the clubhouse at minus-19. After shooting a course-record 62 Friday, Quinney struggled to a 1-over 73 in round three.
He collected just one birdie in his first 10 holes at Brookside Country Club in the final round. Quinney ran off four straight birdies from the 11th to get to 19 under. He closed with four pars in a row and watched the final threesome all come in at that same number.
Compton got to 16 under with birdies on one and four. He gave a stroke back to par with a bogey on the sixth. Around the turn, Compton sank back-to-back birdies from the 12th.
The three-time winner on the Canadian Tour bogeyed the 14th, but caught fire from there. Compton birdied his next three holes to climb to 19 under. He could only par the par-5 closing hole, though, to end in the playoff.
Mallinger bogeyed the second to slip to 15 under. He bounced back with birdies on six and eight. On the back nine, Mallinger birdied three of five holes from the 11th to jump to 20 under.
However, he stumbled to a triple-bogey on the par-5 16th to fall back to minus-17. Mallinger closed with back-to-back birdies to get into the extra session.
Hansen played the front nine at even par, with two bogeys and two birdies, to turn at 16 under. He birdied the 10th, then closed with two birdies in his last three holes to get into the playoff.
In the extra session, the foursome went back to the 18th. Hansen managed to sink a 7-footer for birdie and his first Canadian Tour title.
Rob Oppenheim fired an 8-under 64 on Sunday to finish one stroke out of the playoff at minus-18. Rob Johnson took sixth place at 15-under-par 273 after posting a 65 in the final round.
Adam Speirs was one stroke further back at minus-14 after a 69 on Sunday. Keith Huber and 2002 U.S. Amateur champ Ricky Barnes shared eighth place at 13-under-par 275.