"He had everything going on," Blue Jays manager John Gibbons said. "Good, live fastball, ball had a lot of jump on it, and a good breaking ball."
Johnson struck out a season-high 10 over 7 1/3 innings but remained winless in seven starts with Toronto, having received only 13 runs of support. He said the blister on the middle finger of his right hand, which developed during his June 9 start against Texas and twice delayed his next outing by a day, was not an issue.
"Definitely the most comfortable I've been," said Johnson, who also missed 31 games with a sore right triceps. "Just being able to get extension on all my pitches, not have to worry about the triceps or anything like that. It's definitely nice."
Johnson, who allowed five hits and walked two, lowered his ERA from 5.40 to 4.38.
"He's definitely got some of the best stuff in the game," Colorado's Michael Cuddyer said. "He's big, tall, throws hard. When he's throwing strikes like that, he can be tough. His fastball was getting on guys."
Izturis had two of Toronto's three hits as the Blue Jays won six straight for the first time since May 10-16, 2011.
Rajai Davis singled off reliever Matt Belisle (4-4) to start the eighth, just the second hit of the game for the Blue Jays. Davis stole second and Colby Rasmus walked, with both runners advancing on J.P. Arencibia's slow roller to the mound.
Izturis followed with a bloop single that dropped in front of left fielder Tyler Colvin, scoring both runners.
"He didn't hit it hard, but he dunked it in the perfect spot," Gibbons said. "A nice read at second base by Rasmus there."
Cuddyer singled and walked twice for the Rockies, who went 0-for-8 with runners in scoring position and lost for the fourth time in six games.
Colorado starter Jorge De La Rosa didn't allow a hit until Izturis singled with one out in the sixth. That was the only hit the left-hander allowed in seven shutout innings. He walked three and struck out four.
De La Rosa might have gone deeper, but had to pitch through soreness caused by a bruise on the tip of his thumb.
"In the second inning I threw a two-seamer, and I think the seam caught a bit and that's why there was a little bruise," De La Rosa said. "It was numb a little bit, for like two innings."
De La Rosa had pitched with a cut on his middle finger in his previous two starts.
"My hand hates me," he joked.
Colorado manager Walt Weiss said De La Rosa's thumb issue was not considered serious.
"It's not anything that's going to be an issue with his next start," Weiss said. "It just made him uncomfortable tonight."
The Rockies had several chances to score, but couldn't deliver. Cuddyer extended his hitting streak to 15 games, tying a career high, with a leadoff single in the second. Todd Helton followed with a single, sending Cuddyer to third, but Johnson struck out Wilin Rosario and Colvin, then got Nolan Arenado to fly out.
Arenado ended a streak of 11 straight outs with a two-out double in the fifth, but Jonathan Herrera grounded out.
D.J. LeMahieu hit a one-out double in the sixth and went to third on a grounder by Carlos Gonzalez. Cuddyer walked but Helton ended the threat by popping out.
Herrera singled to begin the eighth and Dexter Fowler walked before both runners advanced on LeMahieu's sacrifice. Cecil replaced Johnson and got Gonzalez to line out sharply to first. Cuddyer was intentionally walked to bring up Helton, who grounded out.
The home team has won all 13 meetings between these clubs, dating to 2002. Colorado is 0-7 at Rogers Centre. ... Toronto SS Jose Reyes (left ankle) went 2-for-3 in five innings of a rehab game with Class-A Dunedin. RHP Brandon Morrow (forearm) started for Dunedin, allowing three runs and five hits in two innings. ... Toronto slugger Jose Bautista was slated to start in RF but switched to DH. Bautista left Saturday's game at Texas because of leg cramps, and started at DH on Sunday. Davis replaced Bautista, and Melky Cabrera moved from DH to LF. ... Carlos Gonzalez started at DH for the Rockies. ... Weiss said the team would make an announcement Tuesday regarding RHP Roy Oswalt, who signed a minor league contract with the Rockies on May 2.