Montreal Impact punished MLS counterparts San Jose Earthquakes with a tight 1-0 win in the CONCACAF Champions League at Stade Saputo.
The Earthquakes had a golden chance to take an 11th-minute lead when Ramiro Corrales' free-kick into the box was handled by Collen Warner and the referee pointed to the spot.
But striker Alan Gordon's weak spot-kick was easily saved by Impact goalkeeper Evan Bush, with usual penalty taker Chris Wondolowski among the substitutes.
Four minutes later, the Impact made San Jose pay as Hassoun Camara shrugged off Gordon's loose marking to direct Hernan Bernardello's cross into the net.
Even with the late introduction of Earthquakes top scorer Wondolowski, an equaliser could not be found with Montreal getting their continental campaign off to the perfect start.
Another MLS side, Sporting Kansas City, also started their campaign positively with a comfortable 2-0 victory at Nicaragua's Real Esteli.
Strikes in either half from Ike Opara and Dominic Dwyer were enough to secure the points as Sporting dominated with five shots on target to Esteli's one solitary effort.
Christian Bermudez scored the game's only goal as Mexico's Club America won at Panama's Sporting San Miguelito.
The Mexican midfielder directed Andres Andrade's assist past San Miguelito keeper Alex Rodriguez in the 24th minute to collect all three points.