"Good Lord," said Red Sox lefty Jon Lester, who worked seven shutout innings for the win. "About 2,000 feet of homers it seemed like. He obviously feels pretty good at the plate. It's fun to watch when we're on that side of it."
Middlebrooks lofted a two-run, opposite-field shot to right as part of a five-run first-inning against Jays ace R.A. Dickey. After doubling in his second at-bat, Middlebrooks drilled a two-run homer to left-center in the fifth. That one also came against Dickey.
He hit his third in the seventh, leading off against right-hander Dave Bush.
There was almost a grand finale in store -- something that would have put Middlebrooks in even more select company. In his final at-bat in the eighth, Middlebrooks smashed one to deep left, and it looked gone off the bat, but Melky Cabrera flagged it down just in front of the wall.
"Hit it too high," said Middlebrooks, whose last three-homer game came in high school. "They must've turned the AC off on me. I thought it had a chance, just the way the ball flies here. I was blowing on it running down the line, but it didn't have enough steam."
The Boston dugout also thought Middlebrooks was about to make his fourth home-run trot of the day.
"From where we were sitting and the reaction in the dugout, yeah, it seemed to be," said Red Sox manager John Farrell. "Especially the way the ball was carrying in this ballpark. Balls were flying out of here left and right, and that's not to take anything away from the power that guys have. When the crowd is full in here, and the temperature is warm, the ball really jumps in here."
The Sox hit six homers, and Daniel Nava, Jacoby Ellsbury and Mike Napoli were the others to go deep.
The most important thing for Boston was taking two out of three from the Jays to finish their season-opening road trip with a 4-2 mark. By contrast, the 2011 team went 0-6 before opening at Fenway. Last year's team was 1-5.
"That's huge," said Middlebrooks. "I feel like we were already going to have momentum going home and playing at Fenway in front of our fans. Everyone was already really excited about that, but to go in rolling like this with 13 runs and Jonny going seven shutout innings, it's huge."
Not only was it the first three-homer game for Middlebrooks, but it was only the second multi-homer game of his career. The third baseman smashed two against the Royals on May 7, 2012. The 24-year-old Middlebrooks was the youngest Sox player to hit three homers in a game since Jim Rice, who was also 24 when he did it in 1977.
It was the first three-homer game by a Boston player since Dustin Pedroia did it in Colorado on June 24, 2010.
"We're counting on him to be a big run producer," Pedroia said. "He's got that ability."
Middlebrooks is proving emphatically that a broken right wrist he suffered last August to end his rookie season won't have any lasting impact.
"Well, everyone is going to point to the three home runs today," said Farrell. "But you look at the slow roller that he made, and he also handles a couple of hot shots down at third base, as well. He's an all-around player, a guy that profiles the position to a T. He's a very good athlete. He was interrupted a year ago because of the broken wrist, but he's clearly back with no restrictions."
Ellsbury (3-for-6), Pedroia (2-for-4), Napoli (2-for-5, four RBIs) and the red-hot Jose Iglesias (.529 batting average) also had multi-hit games.
For Dickey, who won the National League Cy Young Award last season, this was just one of those rare days that happen over the course of a long season.
"You certainly try to forget about it as soon as you can," said Dickey, who exited with two on and two out in the fifth. "Throughout the course of the season, you're going to have a clunker or two that you have to try to forget as soon as you can. Obviously, today was one of those days for me. A lot of this game is about how to handle adversity and manage regret. That will be it for me tonight."
Then there was Lester, who put together a textbook display of what a veteran ace should do with a big lead.
Lester carved up the Jays in a performance that seemed effortless at times, exiting after seven dominant innings -- five hits, no walks, six strikeouts -- with the game well in hand.
A notoriously slow starter for much of his career, Lester has opened this season 2-0 with a 1.50 ERA.
"It feels good, obviously," Lester said. "Anytime you get off to a good start like this, it just adds to your confidence."
And make no mistake about it. The Red Sox are a confident bunch as they get ready to open their 81-game home slate.
"It's huge," said Pedroia. "Last couple of years, we were searching, and now we have a good road trip. Hopefully we can build on the momentum, head home and play even better there."