CHICAGO (AP) Jon Lester felt better Friday, after some rough outings. He knows he wasn't perfect in six shutout innings. A pair of ''pointless, useless walks,'' as he put it, still bothered him afterward.
Not that they mattered, in the end.
The Cubs posted their highest-scoring game at home this season, routing the Seattle Mariners 12-1 Friday for their third straight win.
''The guys swung the bats really well,'' Lester said. ''I try to always tell them, 12 runs and an air-tight defense makes a pitcher's job a lot easier, so that was good today.''
Lester (11-4) gave up four hits and struck out seven.
The lefty had lasted just 16 innings over his previous four starts, going 1-1 with a 10.13 ERA. That skid came after he had gone 9-3 with a 2.03 ERA in his first 16 starts.
''Johnnie Lester, I thought, pitched really well again,'' Cubs manager Joe Maddon said. ''I thought he had a really good fastball today. From the side, to me, it was obvious that his fastball had a lot of jump on it.''
Jason Heyward and David Ross homered as the NL Central leaders won for the 10th time in their last 15 games after a 1-9 slump. They are 9-5 since the All-Star break.
Seattle lost in its first trip to Wrigley since 2007. The Mariners let infielder Luis Sardinas pitch the eighth, and he threw a perfect inning.
Lester matched his win total from last season.
''Jon did a great job settling in after the first couple of innings there and never gave up anything,'' said Cubs right fielder Ben Zobrist, who doubled for the third straight game. ''I think all across the board, as a team, it's a real feel-good win.''
Lester was already done when there was a 74-minute rain delay in the seventh.
Mike Montgomery, traded last week from Seattle to the Cubs, pitched the final two innings. He gave up a single to Shawn O'Malley in the ninth for the Mariners' run.
Hisashi Iwakuma (11-7) had won his last five starts, but gave up five runs and eight hits in three innings. His arm felt tight when he started warming up in the bullpen and never was ''on,'' manager Scott Servais said.
''He got loose and wasn't sharp,'' Servais said, ''missed in the middle of the plate a lot, obviously, against a good offensive club, and it was a rough day.''
The Cubs already led 5-0 when they scored six times in the sixth inning, with Anthony Rizzo hitting a three-run double.
Heyward hit his first homer since June 11 and drove in three runs. He had been just 5 for 45 in his last 13 games.
Kris Bryant reached base all five times he came up for the Cubs. He singled twice, doubled and walked twice. It was Bryant's team-high eighth three-hit game this season.
Sardinas, who played for Texas and Milwaukee the past two seasons, moved from first base to the mound and retired the Cubs on eight pitches.
Javier Baez scored Chris Coghlan's single in the second inning, then turned to see if Ross needed any guidance coming home. Plate umpire Eric Cooper also needed a clean look, and with Baez lingering outside the batter's box, shoved the player out of the way.
''He pushed me really hard,'' Baez said, who added it was nothing personal.
''I guess everyone can laugh about it because I'm not making a big deal out of it,'' he said.
Ross scored easily.
UPS AND DOWNS
The Cubs activated OF Coghlan (ribs) off the disabled list and optioned infielder Tommy La Stella to Triple-A Iowa. La Stella, who was hitting .295 in 105 at-bats with a .388 on-base percentage, didn't take the news well, according to Maddon.
''And he shouldn't take it well,'' Maddon said. ''Honestly, it's just an unusual moment we're in right now where we have so many guys. This is definitely an advocacy for a 27- or 28-man roster.''
La Stella had options remaining, which left him vulnerable in a crowded infield. Coghlan started in LF and the leadoff spot and opened the scoring with a two-run single in the second.
Seattle's Guillermo Heredia made his major league debut when he went to right field in the seventh. He struck out in the eighth. The Mariners recalled him from Triple-A Tacoma before the game and optioned LHP David Rollins.
Mariners: RF Nelson Cruz returned to the lineup after fouling a ball off his shin Tuesday. He went 0 for 2 with a walk.
Cubs: CF Dexter Fowler still has some soreness, Maddon said, so Heyward played center instead of right. Ben Zobrist started in right field for the second straight game.
Mariners: It's been a streaky season for LHP Wade Miley (6-8, 5.23). He lost his first two decisions, won his next six and has lost his last six starts.
Cubs: Jake Arrieta (12-4, 2.76) is 0-2 with a 5.55 ERA in four July starts. He has allowed 20 earned runs over his last five starts after giving up 19 over his first 15 starts.