"I just really wasn't sharp today," Scherzer said. "I didn't really have command of any of my pitches."
With Martinez leading an 11-hit attack, that didn't matter.
"[Martinez] got some awful big hits for us in this series, one right after another," Tigers manager Jim Leyland said.
Martinez went 3 for 4 with three RBIs and Jackson had four RBIs for the Tigers, who have won six of seven to even their record at 18-18.
Martinez extended his hitting streak to a season-high nine games and is batting .438 (14 for 22) over that span. He went 7 for 16 in the four-game series in Toronto with three doubles, one homer and six RBIs.
"When he hits behind Miguel [Cabrera], that's just another quality bat right in the middle of our lineup," Scherzer said. "That just does so much for our offense overall. The complexion of our offense is looking really good right now."
Scherzer has not lost in eight starts this season. His season-opening winning streak is the longest by a Tigers pitcher since Jeremy Bonderman won eight straight in 2007.
"He just couldn't get his release point," Leyland said. "He was all over the place. Just couldn't get consistent. He was hanging his slider a little bit, he just didn't have a good feel for his pitches tonight for some reason."
Scherzer allowed two runs and five hits in five innings, matching his shortest start of the year. He walked three and struck out five.
"The walks kind of killed me," Scherzer said. "They ran my pitch count up and didn't allow me to go six."
Toronto lost for the seventh time in nine games and dropped a season-high five games below .500.
Ryan Perry walked the bases loaded in the ninth before giving up a two-run double to Corey Patterson and, one out later, an RBI single to Edwin Encarnacion. Jose Valverde came on after Perry hit Aaron Hill with a pitch and ended it by getting Juan Rivera to ground out.
"He was just real stale because he hadn't pitched," Leyland said of Perry, who last worked May 2 against the New York Yankees. "I don't have any problem with that. I felt bad really, because it was seven days since he pitched. That's why I was getting guys work tonight."
Blue Jays right-hander Brandon Morrow (1-2), who had allowed just one hit and one walk through the first three innings, fell apart in the fourth, when the Tigers scored six runs and sent 10 batters to the plate.
Brennan Boesch struck out to start the inning but reached safely when catcher Jose Molina couldn't hang onto the third strike. After Cabrera walked, Martinez hit an RBI double and Don Kelly followed with a run-scoring single.
Jhonny Peralta lined out hard to shortstop and Morrow was yanked after walking Alex Avila to load the bases. Shawn Camp came on and fanned Ryan Raburn, then gave up a three-run double to Jackson and an RBI double to Ramon Santiago.
Leyland called Jackson's double "huge, [the] biggest hit of the game."
Morrow allowed five runs and three hits in 3 1/3 innings. He walked three and struck out six. The right-hander twice slammed his glove down in frustration after returning to the dugout.
"Things just started to snowball a little bit," he said. "I could have made a better pitch definitely to Martinez, it was a slider that really didn't do anything. That's really what broke it open."
Detroit added four more in the seventh off reliever Octavio Dotel, again sending 10 batters to the plate. Martinez homered to right, his third, Raburn hit an RBI single and another run scored on Encarnacion's throwing error at third base.
Kelly left the game with a sore right ankle after being hit by a pitch in the seventh. He was replaced by Brandon Inge at third base.
Scherzer is 3-0 with a 6.23 ERA on the road and 3-0 with a 0.96 ERA at home. ... Blue Jays 1B Adam Lind missed his second straight game with a sore lower back. ... Inge, Magglio Ordonez and Scott Sizemore were held out of the starting lineup for Detroit. ... Boesch twice made the final out in 10-batter innings, grounding out to end the fourth and seventh. ... Encarnacion has made seven errors this season, second in the AL to Texas SS Elvis Andrus, who had eight entering play Monday. ... Attendance was 11,785, Toronto's third-smallest crowd of the season.