In the seventh, Hawpe caught Jose Lopez's short fly ball and threw out Yuniesky Betancourt. Now the Mariners know why he has 11 assists this season.
"You can read a scouting report that says somebody throws the ball well, but until you're actually on the field, you don't really realize the skills people have," said Hawpe, who also homered in Friday night's series opener.
After taking on the Rockies (42-39), the American League teams have to be glad they won't do so anymore this season. The Rockies went a National League-best 11-4 in Interleague Play, starting with a sweep of the Blue Jays and series victories over the Athletics, Rangers, Angels and Mariners. All except the Angels had been on lengthy hot streaks.
The Rockies are now a half-game behind the first-place Padres going into a pair of three-game sets at Coors Field against divisional foes -- the Giants starting on Monday and the Diamondbacks starting on Friday. The Rockies' 13-17 record against the NL West is the worst among the five teams.
"We took advantage of it this year," manager Clint Hurdle said of the Interleague schedule. "Now we've got the NL West in front of us. We'll look forward to that."
Hawpe's assist kept the Mariners at a 2-1 lead, and after the Rockies tied it in the eighth and forced extras, he was there again to win it.
Matt Holliday led off the 11th with a double off Julio Mateo (5-2) that bounced past first baseman Willie Bloomquist. Three batters later, Hawpe knocked a soft liner to right-center off Eddie Guardado that Jeremy Reed dove for but could not glove. Reed broke his right thumb on the play.
Hawpe has faced questions about his abilities against lefties, but he homered off Jamie Moyer on Friday and knocked in the go-ahead run off Guardado.
"Guardado's got good stuff -- a sneaky fastball and good slider -- and has been around a while and knows what he's doing," said Hawpe, who later scored on JD Closser's bloop single to give the Rockies a 4-2 lead. "That's part of playing long games -- you get some opportunities to come up big."
Scott Dohmann yielded a one-out homer to Ichiro Suzuki -- who went 3-for-5 and finished a double shy of the cycle -- and a two-out single to Lopez in the bottom of the 11th.
But Ray King earned his first save of the season by forcing Raul Ibanez to fly out to deep center. It was his second career save and first since June 19, 2001, when he was with the Brewers.
King had given up runs in six of his previous eight appearances and been replaced in a late-inning relief job by Tom Martin, who struck out the only batter he faced on Sunday.
"Everybody's making a mountain out of a molehill," King said. "I got moved to a different situation. It's not something I'm happy about, but I pitch for the team. Today was a situation where we needed an out, somebody got it, and we got a 'W.' "
Starter Jason Jennings turned in his fourth straight stellar start (1.24 ERA), going seven innings and giving up seven hits, including Richie Sexson's two-run homer for a one-run deficit in the sixth. Jennings faced runners at second and third with one out in the seventh, but Hawpe's throw kept the inning scoreless.
Mariners starter Jarrod Washburn matched Jennings, holding the Rockies to two runs and six hits in seven innings. Washburn had a 2-1 lead when he began the eighth with two walks and a single to load the bases. Mariners closer J.J. Putz retired the next three, but the second out was Garrett Atkins' sacrifice fly, which plated the tying run.
In the bottom of the ninth, Ichiro tripled with one out, and the Rockies instructed Jose Mesa to intentionally walk the next two hitters to load the bases for closer Brian Fuentes (2-1).
"I had no idea," Fuentes said when asked if he realized beforehand that the Rockies planned to give him loaded bases. "They told me to get up, fast. I was kind of taken by surprise.
"But once I got out there, those weren't Mesa's [potential] runs, they were mine."
Fuentes fanned Ibanez on four pitches, worked Bloomquist into a grounder to the mound and ended up striking out two in 1 2/3 innings.