Dexter Fowler, Jason Heyward, Addison Russell and Matt Szczur each homered for the Cubs, who rallied to tie the game at 7 in the fourth after trailing 7-1. Chicago has hit 30 home runs in the last 20 games.
Cano, who is returning from double hernia surgery, hit his fourth spring home run with one out and one on in the first off an 0-2 pitch from Jason Hammel. The Mariners second baseman added a three-run shot in the second, and a two-run homer in the eighth off Trevor Cahill.
"Happy Easter, Robbie Cano, I guess," Hammel said. "He had one heck of a game today. Obviously, my execution has to be better down in the zone, but that was because of being a little quick up top. That was always my mistake before. Today, I was trying to create when I didn't need to."
For the game, Hammel gave up nine runs on eight hits over 4 1/3 innings.
"Numbers-wise, you look at the line and yuck," Hammel said. "I did get the work in today. I did better with the sequencing today."
Mariners starter James Paxton served up three of the Cubs home runs. He said he left some pitches up on a day he obviously needed to work down with the ball carrying so well, but the southpaw had a career 6.75 ERA in 16 previous Cactus League games and feels it's a tough situation to judge his progress as he competes with Nathan Karns for the fifth starter spot.
"I think so. Obviously, it's what the coaches think that matters," Paxton said. "But I've kind of been that guy that doesn't get the numbers in Spring Training my whole career. I'm not going to let this start bother me. I'm just going to keep working and get myself ready for the season."
The Mariners loaded the bases with two outs in the second and Ketel Marte lofted a ball toward the left-field line that deflected off Russell's glove. Two runs scored on the double to give Seattle a 4-1 lead. Cano then launched his second homer to open a 7-1 lead.
The Cubs rallied, sending nine batters to the plate in the third to close to 7-6 as Heyward hit a two-run homer and Russell belted a three-run shot, his fourth, which is tied for the team lead this spring. Mark Zagunis tripled to open the fourth and scored one batter later on Kris Bryant's single to tie the game.
Seth Smith smacked a two-run double with one out in the fifth to give Seattle the lead and chase Hammel. Cano crushed a two-run homer in the eighth against Trevor Cahill.
Play was stopped in the Mariners' third after a swarm of bees invaded Sloan Park. Heyward tried to escape by jumping onto the fence in center, and Cubs relievers shared the visitor's bullpen in right field to avoid being stung.
Up next for Mariners: Right-hander Nathan Karns, competing with James Paxton for the final rotation berth, gets the start Monday in a 1:10 p.m. PT game against the Royals at Peoria Stadium. Karns is looking to bounce back from a rough outing against the A's (eight hits and nine runs, seven earned in 2 1/3 innings). The game will be televised on MLB.TV.
Up next for Cubs: Kyle Hendricks will make his fifth Cactus League start on Monday when the Cubs travel to Tempe to play the Angels. The right-hander has been effective this spring, striking out 19 over 19 innings. He's projected for the fifth spot in the rotation. First pitch is scheduled for 3:10 p.m. CT, live MLB.TV and a free cubs.com audio webcast.