"It's the first Spring Training game," Cano said. "I didn't want to just go up there and take a pitch. You want to see how you feel."
Padres starter Eric Stults gave up three runs on three hits in two innings, including a run-scoring double by Justin Smoak in the first that plated Cano.
Donn Roach pitched two scoreless innings in relief of Stults as the right-hander allowed just a single and a walk. Roach, 24, pitched at Double-A San Antonio last year and is in his first Major League camp.
Mariners starter Erasmo Ramirez hurled two shutout frames, giving up two singles with no walks and a strikeout on 29 pitches. Blake Beavan followed with two more scoreless innings on just a single and walk.
Logan Morrison, playing his first game since being acquired by trade from the Marlins, went 2-for-2 with an RBI on a sacrifice fly in his Mariners debut at designated hitter.
The Mariners doubled their lead to 6-0 in the sixth inning, though just one of the three runs was earned. Padres lefty Patrick Schuster surrendered four hits in that frame, including RBI singles by outfielder Xavier Avery and catcher Humberto Quintero.
The Padres broke through in the eighth inning following Rico Noel's leadoff double. After moving to third on Reymond Fuentes' groundout, Noel crossed on Cory Spangenberg's grounder to short.
Up next for Padres: It will be the Padres and Mariners again from Peoria on Friday at 12:05 p.m. PT. Andrew Cashner, who is considered a strong contender to start Opening Day, gets the start for the Padres and will likely throw two innings. New reliever Joaquin Benoit, who signed a two-year, $15.5 million deal with the team during the winter, is also scheduled to throw one inning. Joe Wieland, who missed all of 2012 while recovering from Tommy John surgery, is also slated to throw one inning.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.