Fellow Toronto newcomer Robbie Findley also scored. Octavio Rivero scored for Vancouver.
Altidore tied at 1 in the 32nd minute after some great work by Sebastian Gionvinco. The Italian slid a pass through to Altidore and the U.S. national team star beat David Ousted from a tight angle.
Findley made it 2-1 in the 59th minute, scoring off a cross.
Altidore completed the scoring on a late penalty after being dragged down by Pa-Modou Kah.
D.C. UNITED 1, IMPACT 0
WASHINGTON (AP) — Jairo Arrieta scored in the 58th minute and D.C. United beat Montreal for the Washington club's first season-opening victory since 2011.
After Bill Hamid's save, D.C. United pushed the ball up field and Arrieta slid the ball under Evan Bush, who had come out to the corner of the 18-yard box to attempt an interception of Chris Rolfe's lofted pass. Three minutes later, United's Chris Pontius hit the crossbar from just outside the 6-yard box.
United was without its two leading goal scorers from last season. Luis Silva has a hamstring injury and Fabian Espindola is on suspension.
RAPIDS 0, UNION 0, TIE
CHESTER, Pa. (AP) — Colorado held off Philadelphia's second-half charge as the 10-manned Rapids played to a scoreless draw with the Union.
The Rapids had three 0-0 games last season and the Union played in two.
Colorado's Bobby Burling received his second yellow card in the 68th minute after a takedown of Sebastien Le Toux near midfield.
DYNAMO 1, CREW 0
HOUSTON (AP) — Giles Barnes scored in the 66th minute, Tyler Deric made five saves for the shutout and Houston beat Columbus for coach Owen Coyle's first MLS victory.
Kofi Sarkodie took a long forward pass from Raul Rodriguez and made a run on the right. He froze Waylon Francis with a stop move, and then fed Barnes at the penalty spot. Barnes' shot settled past the outstretched hand of Steve Clark and just under the crossbar.
FC DALLAS 1, EARTHQUAKES 0
FRISCO, Texas (AP) — Blas Perez scored on a header in the 92nd minute and FC Dallas beat San Jose.
Perez was 6 yards out when he redirected a blast that Moises Hernandez sent wide. It was Perez's 32nd career MLS goal.
The loss extended the Quakes' franchise-record winless streak to 16 games in coach Dominic Kinnear's return to the club after a 10-year absence.
REAL SALT LAKE 0, TIMBERS 0, TIE
PORTLAND, Ore. (AP) — Real Salt Lake's Nick Rimando made five saves to fend off Portland.
Real Salt Lake has not lost in its past six season openers, all of them on the road.
The match marked the Portland debut of Nat Borchers, who spent seven years with Salt Lake. Borchers, a two-time MLS defender of the year, was a key contributor on Salt Lake's 2009 MLS Cup-winning team.