"That's why everybody was going crazy when we were losing all those games at the beginning of the season," Ortiz said. "Because you go position by position, this team can match against anybody."
Adrian Gonzalez and Dustin Pedroia also homered for Boston in support of Jon Lester, who pitched two-hit ball over eight innings. Gonzalez drove in two runs and Pedroia three for the Red Sox, who never trailed in the series against their division rivals.
Lester (9-2) kept the Blue Jays off balance all afternoon while winning his league-best ninth game. The ace left-hander walked just one batter and struck out eight while earning his second win in three starts against the Blue Jays this season.
"Guys came out and swung the bats well and kind of it seemed took the life out of them a little bit and we were able to take advantage of that," Lester said. "I don't think I've ever really seen a stretch like these past nine games that we've been playing as far as scoring runs and the way our pitchers have been throwing the ball."
Boston's league leading offense had 17 hits a day after amassing 18. After scoring seven runs in the fifth inning Saturday, Boston scored six more in the fifth in the series finale.
Toronto's Jose Bautista ended a 13-game homerless drought with his 21st of the season in the fourth.
The first seven Red Sox in the inning all reached base, the first five against Blue Jays rookie starter Kyle Drabek.
"I'm very frustrated right now," Drabek said. "I couldn't tell you the last real quality game that I've had. It's frustrating walking people, giving up hits, not giving your team a chance to win."
Jacoby Ellsbury singled to start it off before Dustin Pedroia homered to extend Boston's lead to 5-1. Gonzalez doubled and Youkilis walked ahead of Ortiz. Big Papi then hit his 17th home run of the season and fourth in six games.
"I'm not thinking about anything right now, trying to keep my mind clean, as clean as day and play," he said. "I don't want to think about anything and get it stuck in my head and then next thing you know you work out of your rhythm."
Ortiz's current run is causing many of his teammates to marvel at the 35-year-old.
"Every ball he hits is on the barrel the other way and when he's turning on balls, he's a force, man," said Pedroia. "He's not just a home run hitter, he's a hitter and I think he knows that makes our team go."
With Ortiz's homer, Drabek was done after four-plus innings. Drabek (4-5) gave up eight runs, seven hits and four walks.
The 23-year-old son of former NL Cy Young winner Doug Drabek threw just 45 of his 91 pitches for strikes as his ERA jumped 4.98 to 5.70.
Little changed after reliever Luis Perez took over for the Blue Jays. The left-hander who had not allowed a run in 12 2-3 innings gave up an RBI single to Marco Scutaro.
Youkilis, Ortiz and Jarrod Saltalamacchia each added RBI doubles off Perez in the sixth that pushed Boston's lead to 12-1.
Gonzalez connected in the first for his 13th home run. The American League RBI leader has driven in at least one run in nine consecutive games, extending his new career-high and setting a new season-best mark for the AL.
Gonzalez also had an RBI groundout.
Youkilis capped the scoring with his ninth home run of the season, off Blue Jays closer Jon Rauch.
Lester retired the first 11 batters he faced before Bautista trimmed Boston's lead to 3-1 with his 21st home run of the season.
"I'm seriously not making this season out to me hitting home runs," said Bautista, last year's major league leader with 54 home runs. "I'm trying to win games and we didn't get it done today. The fact that I got a home run, it could have been a single, it would have been the same difference. We only scored one run today and it wasn't enough."
Notes: Red Sox manager Terry Francona sat Jed Lowrie on Sunday and said the shortstop could get another day off to help his sore right shoulder heal. ... Ortiz interrupted Francona's morning meeting with the media to give the manager a pair of Boston Bruins hats to try on. The Bruins are playing in the NHL's Stanley Cup Finals against the Vancouver Canucks. ... According to the Elias Sports Bureau, Gonzalez's nine-game RBI streak is the second longest in team history behind only Dwight Evans' 10-game run from Sept. 15-26, 1989. ... The Baltimore Orioles announced Chris Jakubauskas will start Tuesday's opener of their three-game series at Toronto. Ellsbury's fifth-inning singled extended his hitting streak to 10 games Boston's nine-game winning streak is the franchise's longest since an 11-game run Apr. 15-27, 2009.