Teixeira hit his AL-leading 25th homer and DeRosa had a two-run shot in a four-run eighth inning as the Rangers completed a three-game sweep of the Toronto Blue Jays with a 9-8 victory Sunday.
DeRosa was making a rare start in place of All-Star second baseman Alfonso Soriano, who was in Panama to be with his wife, who is expecting the couple's second child.
With the game tied at 5, Sandy Alomar drew a out-out walk in the eighth from Jason Frasor (1-4). DeRosa, without a hit in his first three at-bats and carrying a .182 average at the start of the day, followed with his third homer of the season.
"After I struggled in my first three at-bats, there were a couple of guys in the crowd calling for Soriano," DeRosa said. "I'm glad they stuck with me."
DeRosa, making his 14th start, knows how to handle a bench role after serving in that capacity for the Atlanta Braves last season. For Texas, he's the backup for Soriano, Teixeira and Michael Young.
"I got three All-Stars playing my positions, so my time out there is just to give them a rest," DeRosa said. "I understand my role."
David Dellucci followed with a single, went to second on a groundout and scored on Teixeira's two-run drive off Justin Speier to extend Texas' lead to 9-5.
Teixeira, the AL All-Star first baseman, has three homers in his last two games and seems ready for Monday's Home Run Derby in Detroit.
"This is a job. It's work," Teixeira said. "(Monday) will be fun. I just want to hang out there and whatever happens, happens."
Aaron Hill's two-run double in the ninth off Francisco Cordero pulled the Blue Jays within 9-7. Eric Hinske's run-scoring double made it 9-8, but Cordero struck out Alex Rios with runners on second and third before getting pinch-hitter Reed Johnson to ground to third to end it.
Hank Blalock had three RBI for the Rangers. Kameron Loe (3-1) pitched a hitless eighth for the victory.
Vernon Wells' three-run double in the fifth gave the Blue Jays a 4-3 lead, knocking out Rangers starter Chris Young.
But Texas came back in the fifth against Toronto starter Josh Towers, getting consecutive singles from Dellucci and Michael Young. After Teixeira walked to load the bases, Blalock singled to right to drive in Dellucci and Young.
The Blue Jays tied it at 5 in the eighth on Rios' RBI groundout against Loe.
Gregg Zaun had three hits for the Blue Jays, who have lost 10 of their last 13 in Arlington.
Texas took a 2-0 lead in the second on Gary Matthews Jr.'s run-scoring double and Alomar's RBI single. Blalock had an RBI double in the third, but Zaun cut the deficit to 3-1 with a run-scoring single in the fourth.
Chris Young allowed four runs and six hits over four innings on a hot afternoon, and he has an 8.10 ERA over his last five starts to raise his ERA from 2.78 to 4.01.
"A lot of people run out of gas," Rangers manager Buck Showalter said. "We're trying to be as careful as we can with him. I think Chris is probably a little weary right now."
Blue Jays manager John Gibbons said Frasor's walk to the 39-year-old Alomar, the backup catcher making his 20th start of the season, was a mistake.
"You can't walk Sandy Alomar Jr.," Gibbons said. "That's the game right there. Those passes burn you."
Frasor made no excuses.
"That certainly kick-started things for them," Frasor said. "You get behind the next guy and in 30 seconds it's 7-5. I couldn't get my breaking ball over and I left the fastball out over the plate. You know what those guys can do with those kinds of pitches."
- The Rangers honored former OF Rusty Greer in pregame ceremonies.
- Michael Young has at least one extra-base hit in each of the last eight games.
- Hill extended his hitting streak to 11 games.
- Toronto's Shea Hillenbrand has hit safetly in 23 of 24 career games against Texas.