It's working pretty well this season.
Stairs, 39, went 4-for-5 with a homer and two RBI and scored twice. It was the third four-hit game of his career and first since June 14, 2000, at Minnesota.
"I don't know where we'd be without him," Blue Jays manager John Gibbons said.
Thomas, who turned 39 on May 27, finished 4-for-4 with four RBI and a walk.
"It was a great day to be 39," Stairs said.
Thomas said he and Stairs share a passion for hitting.
"I've played with Matt a long time," Thomas said. "He's a great hitter. He's always been a great hitter. He's brought a spirit to this clubhouse every day and it's been great."
Toronto pushed across two runs in the sixth to take an 8-6 lead. Pinch-hitter Gregg Zaun drew a one-out walk and John McDonald reached on first baseman Jeff Baker's error, putting runners at second and third.
"Garrett (Atkins) made a nice play and threw the ball over there," Baker said. "It caught me late and I just missed it."
Jorge Julio replaced starter Aaron Cook (4-5) and gave up a run-scoring groundout to Vernon Wells, then hit Alex Rios with a pitch. Left-hander Tom Martin came on to face Stairs, who hit an RBI double to right.
"Our offense has struggled most of the year, but I think guys are going up there starting to get hot, swinging the bats well, not trying to do too much," said Stairs, who is hitting .309 with 11 homers and 26 RBI.
Cook allowed six earned runs and nine hits over 5 1/3 innings to lose his fourth straight decision. The right-hander, who walked three and struck out none, hasn't won since May 26 at San Francisco.
"It's not the kind of start we're looking for," manager Clint Hurdle said. "He's got some work to do."
Rockies catcher Yorvit Torrealba was ejected for arguing balls and strikes after striking out to end the fourth. Torrealba, who was replaced by Chris Iannetta, claimed plate umpire Gerry Davis was squeezing Cook.
"It seemed like he wasn't getting those calls on the corner," Torrealba said. "Everything had to be right down the middle."
Cook said his problem was location.
"I was getting it up a little bit," he said.
The Blue Jays took a 3-0 lead in the first. Stairs homered to left, Troy Glaus doubled and Thomas followed with a two-run homer, his 11th.
"I'm feeling good at the plate, recognizing pitches early," Tulowitzki said.
The Blue Jays, who finished with a season-high 17 hits, led 6-3 before Colorado scored three times in the sixth. Baker and Iannetta had run-scoring groundouts and a throwing error by Stairs led to a third run.
Making his season debut in place of the injured A.J. Burnett (sore shoulder), Toronto right-hander Ty Taubenheim allowed five runs and five hits over five-plus innings. He walked four and struck out four.
- Stairs is tied for the major league lead with seven interleague homers.
- Actor James Denton (Desperate Housewives) threw out the first pitch.