Toronto starter Ricky Romero's biggest problem during his career has been wildness. It showed up right away on Wednesday.

Romero threw 16 of his first 19 pitches for balls, leading to a pair of walks that triggered Boston's six-run first inning, and the Red Sox coasted past the Blue Jays 10-4.

"Well, we've seen a couple of games earlier in the year where Ricky had some command issues. They obviously showed up again here today," Blue Jays manager John Farrell said. "Physically, everything is fine. It's a matter of having conviction, trust and overall belief in the stuff that he possesses."

Romero (8-2) left after giving up six walks, seven hits and nine runs in three-plus innings.

"I just didn't do my job today," he said. "I'm just embarrassed in myself more than anything. I feel like I let the team down."

It was his shortest and worst outing of the season. Now, he's trying to figure out what went wrong.

"I've had some times (like that) last year," he said. "But right now when I'm missing, I'm missing bad. I'm not even coming close."

David Ortiz hit his 399th career homer, Adrian Gonzalez had three RBIs and Mike Aviles drove in two as the Red Sox improved to 9-2 in their last 11 games.

Jon Lester (5-5) fell behind 1-0 in the first when he allowed a run-scoring single to Colby Rasmus, but the Red Sox scored all the runs they needed in the bottom half.

"Bad day. I didn't locate and didn't throw strikes," said Romero, sounding very dejected. "You can't give free passes to a team like that. You can't give free passes to anyone. Just a bad day. I was disappointed I didn't come through for the team. We had a chance to win the series. I just didn't do my job."

Boston went ahead 7-1 in the second when Ortiz and Cody Ross walked on 3-1 pitches and Gonzalez hit an RBI single.

Jose Bautista hit a solo shot, his major-league leading 25th homer of the season, off Lester in the fourth. But the Red Sox struck back with two runs in the bottom of the inning. Gonzalez singled in one and Aviles drove in the other.

Ortiz made it 10-2 in the fifth with his 21st homer of the year. His 399 career homers are tied for 49th with Andres Galarraga and Al Kaline. Duke Snider is 48th with 407.

Lester, who was just 1-2 in his previous six starts, retired eight consecutive batters before running into trouble with two outs in the sixth. He allowed a double to Bautista followed by Edwin Encarnacion's 22nd homer. Ben Francisco then singled, but Yunel Escobar flied out to end the inning.

Lester pitched seven innings, striking out four with no walks, seven hits and four runs.

Romero was in trouble from the start. He had averaged 4.4 walks per nine innings this season but walked a total of just nine batters in his last four starts.

He walked leadoff batter Daniel Nava on four pitches then threw two balls to Dustin Pedroia before his first strike. Pedroia doubled in Nava and the next batter, Ortiz, walked on four pitches before Romero started Ross with two more balls.

Ross then singled, loading the bases, and Gonzalez reached on an error by third baseman Encarnacion, allowing Pedroia and Ortiz to score. Will Middlebrooks followed with an RBI groundout, Aviles singled in one run and Darnell McDonald singled in another, making it 6-1.

Notes: Toronto, in last place in the AL East, dropped two games behind Boston ... Romero was 4-0 in his last seven starts but had given up at least four runs in each of his last six games. Wednesday's start was his shortest of the season and the runs allowed were his most.... Bautista leads the majors with 16 road homers. ... RHP Henderson Alvarez, who left Monday night's 9-6 Toronto win with right elbow soreness, is expected to start on Saturday after undergoing an MRI that shows some inflammation, Farrell said.