It was the team-leading 19th home run for the 41-year-old Ibanez.
"This team, for whatever reason, we do the hard part well. We score late in the game, and that's the hard part," Ibañez said. "The hard part is hitting against setup [pitchers], closers, late in the game, and I think we do that part well. We're good at coming back. I think if, offensively, we can hit collectively the first six innings the way we do in the last three, we'll be a really good team."
Jeremy Bonderman lasted only 3 1/3 innings for the Mariners, giving up six runs (four earned) on six hits. After a 1-2-3 first inning, the Cubs started to tee-off on the right-hander.
"He left a few breaking pitches up today. I think we hurt him mostly on breaking balls," Chicago second baseman Darwin Barney said. "A lot of the video we saw, his breaking stuff was down and tough. We were looking for elevation, and the few he left up, maybe we got lucky and hit a few holes. We put some good swings on."
Chicago took an early three-run lead in the second inning, thanks to doubles from Alfonso Soriano, Anthony Rizzo, Brian Bogusevic, and Barney. Seattle had led the game off with a double of its own, courtesy of Endy Chavez, but was unable to bring the runner home.
A bright spot for the Mariners was the play of shortstop Miller. Called up for his superlative hitting in Triple-A Tacoma, Miller had gone hitless in his first two starts with the big league club. The 23-year-old collected his first two Major League hits on Sunday, both doubles.
"I like his approach up there. He's ready to hit, and he sees the ball," manager Eric Wedge said. "He's out of the box looking for doubles and triples. The way he runs and his attitude and approach to the game, he's going to hit a lot of doubles and triples in his time. Good to see him get that first one and a hustling double the second one."
Another bright spot was the continued excellence of long-reliever Blake Beavan. Although Bonderman was shelled early, Beavan was able to carry the Mariners through the eighth inning, allowing only one run and three hits while striking out four batters in 4 2/3 innings of work.
Bonderman's struggles continued in the third inning. After hitting Nate Schierholtz to put him aboard, Bonderman walked Rizzo and Dioner Navarro to load the bases. However, Bogusevic's deep shot to left field fell just short of the wall, allowing Bonderman to escape the jam.
"He never really got it going today," Wedge said. "They were laying off some tough pitches and hitting ones over. They were squaring them up pretty good there. He's a battler. He's trying to find it and get through, but ultimately we had to get him out of there."
Seattle scored on a fielder's choice in the third inning. Henry Blanco made it home on a groundout from Nick Franklin after singling and advancing to third on another double by Chavez.
Chicago extended its lead in the fourth. After Barney doubled, an easy grounder from Welington Castillo bounced through Seager's legs, plating Barney and sending Castillo to second base. Castillo scored on a single from Starlin Castro, prompting Wedge to replace Bonderman with Beavan.
Before Beavan could end the inning, however, Soriano hit a double to score Castro from first. Soriano scored on a single from Rizzo, putting Chicago up, 7-1.
The loss drops the Mariners to 35-47 on the season. The Cubs, who won the three-game series, 2-1, improve to 35-45.
The Mariners attempted a rally in the seventh. After Jason Bay hit a solo home run to right field, Miller added his second double, prompting Cubs manager Dale Sveum to pull Jackson. Reliever Shawn Camp retired Blanco, Chavez, and Franklin to end the threat.