As far as starting pitcher Edwin Jackson is concerned, the only important part was that the Cubs hung on for a 7-6 victory.
"An ugly win is better than a pretty loss any day," Jackson said. "We were fortunate enough that we had a lot of runs so when they did come back and score there we were still winning. That's the most important thing, when you come out of the inning that you're still winning, regardless of how they came back."
Chicago led 7-1 after four innings. The Mariners comeback started against Jackson (4-10), who pitched into the seventh inning, allowing three runs and seven hits and striking out six. But it really got going once the game was turned over to the Cubs' bullpen, which has blown 16 save chances this season and gave up three runs in the eighth against Seattle.
"It looked real easy for a while, but we all know that's why we play nine innings," Cubs manager Dale Sveum said.
It was jokingly suggested to Sveum the Cubs might prefer only playing seven innings to cut out the late-inning issues with the bullpen.
"No kidding," Sveum said, laughing. "If we go back to Little League days, we'd be OK."
The Cubs tied a season high by hitting six doubles, including two each by Alfonso Soriano and Darwin Barney. Anthony Rizzo drove in two runs for Chicago, which took two out of three in the series against Seattle.
Kevin Gregg pitched a hitless ninth for his 13th save, a day after blowing his first save chance of the season.
"I want to pitch every day," Gregg said. "Coming off a blown save yesterday, I want to get right back out there. I don't want to sit on it at all."
Seattle starter Jeremy Bonderman (1-2) was chased after giving up six runs -- four earned -- and six hits in 3 1/3 innings. It was his shortest start since going 2 1/3 innings on July 29, 2007 with Detroit.
The loss was the first for Bonderman since being called up June 2 and making his first major league appearance since 2010. That time out, he gave up seven runs in 4 2/3 innings, but since he had been on a roll, giving up a total of four runs in the four starts before Sunday.
Bonderman's trouble against the Cubs started in the second inning when the Cubs doubled four times, leading to three runs. Soriano and Rizzo led off the inning with doubles, and with one out Brian Bogusevic and Barney hit back-to-back RBI doubles.
"Doubles are good. Runs are better," Barney said. "Once something good happens, good things start going through your mind, and that's the whole battle in this game."
In the fourth, Barney led off with another double and scored when Wellington Castillo's grounder to third went through Kyle Seager's legs for a two-base error. Starlin Castro's run-scoring single marked the end for Bonderman.
Reliever Blake Beavan gave up an RBI double to Soriano and another run on Rizzo's single as the Cubs took their 7-1 lead. That was the end of the offense for Chicago, which managed only one hit over the final five innings.
"At this level you can't ever assume," Barney said. "Once you start assuming, you start laying down a little bit. That's just not a luxury we have -- or anyone has."
The Mariners' comeback got going in the fifth when Nick Franklin's single drove in a run. Bay's leadoff homer in the seventh cut the lead to 7-3.
Raul Ibanez led off the eighth with his 19th home run of the season against reliever Shawn Camp. Kendrys Morales singled and Seager broke an 0-for-19 slump with a deep home run down the right-field line to bring the Mariners within a run before reliever Hector Rondon and Gregg shut down the rally.
"We had our opportunities, fought back and got close," Seattle manager Eric Wedge said. "But that's not good enough."
Cubs OF Ryan Sweeney will be placed on the disabled list after breaking a rib on his left side crashing into an outfield wall. Sweeney will be held out of baseball activities for four to six weeks. ... Seattle CF Dustin Ackley should be able to return "in a couple days" after spraining his right thumb Saturday, manager Eric Wedge said. "All things considered, could be a lot worse," Wedge said.