Robertson, who threw complete games in two of his previous three starts, was tossed for throwing his only pitch behind a batter in retaliation for Tampa Bay's Scott Kazmir hitting Placido Polanco in the leg with the first pitch of the game.
The left-hander spent the rest of the night watching the Tigers' bullpen sparkle on the way to a 7-3 win that extended Tampa Bay's losing streak to 10 games.
"You know what? We won the game, and it's a good win," Robertson said after Detroit won for the fourth straight time since falling a season-high six games under .500 earlier in the week.
Despite pitching well, Robertson has lost his last two decisions -- 2-1 to Chicago and 1-0 to New York -- because of a lack of run support. This time, the Tigers gave him a four-run before he even stepped on the mound.
"It's just a pitch that got away from me," Robertson said, denying that he threw at leadoff man Carl Crawford. "Bottom line, it just got away from me."
The Tigers starter also scoffed at the suggestion that he wasted a good opportunity to win.
"I didn't lose anything. It's not about my record," Robertson said. "It's not about anything that I do, as long as we win the game."
Craig Monroe homered and had a season-high five RBI for the Tigers, including a two-run, first-inning single that came one pitch after right fielder Aubrey Huff overran a fly ball that should have been caught in foul territory for the third out.
Monroe added a sacrifice fly off Kazmir (3-7) in the third and hit a two-run homer off Dewon Brazelton for a 7-0 lead in the seventh.
Franklyn German (3-0) replaced Robertson and allowed one hit in three innings to get the victory. Fernando Rodney yielded one hit in three scoreless innings before the Devil Rays broke through against Doug Creek, scoring on Toby Hall's sacrifice fly in the seventh and Nick Green's two-run homer in the ninth.
The loss was the 13th in 14 games for the Devil Rays, and their 10-game skid matches the longest in the majors this year. Colorado lost 10 straight April 24-May 7.
Plate umpire Tim McClelland immediately tossed Robertson when the left-hander's pitch sailed several feet behind Crawford.
Tigers manager Alan Trammell briefly argued the ejection while German was summoned from the bullpen. He said he didn't see the pitch because he was making notations about the Tigers' four-run first.
"I don't normally miss the first pitch. That was the farthest thing from my mind. We have a four-run lead, I'm feeling pretty good. ... My balloon got burst real quick," Trammell said.
McClelland didn't issue a warning when Kazmir hit Polanco because he didn't feel it was intentional. The 21-year-old rookie began the night leading the AL in walks and Polanco is the seventh batter he's plunked this season.
"It was the first pitch of the game. There wasn't any history or anything. Polanco hadn't been hitting the ball, he hadn't done anything to merit being thrown at. I just think the pitch got away from him," McClelland said.
The crew chief didn't feel the same way about Robertson's lone pitch.
"When it's three feet behind a guy, yeah, then I'm pretty sure that's intentional," McClelland said.
Kazmir denied throwing at the Tigers' leadoff man.
"There was no way I had any intention against Polanco. ... It was just the first pitch, trying to go inside with it. It just flew out and went straight for him."
Tampa Bay manager Lou Piniella went to his bullpen after Kazmir faltered in the third.
McClelland issued a warning to the left-hander before the start of the second, but did not eject him when Kazmir threw wildly behind Vance Wilson before walking the Tigers catcher with two outs in the third.
Kazmir threw 74 pitches in three innings, allowing five runs and five hits. He walked four, giving him 56 in 102 innings.
"He struggled with his command the whole time," Piniella said. "The amazing part about it is the Detroit pitcher must have thought he hit the guy intentionally, which couldn't be further from the truth."
Jonny Gomes singled with one out in the third for the only hit off German, who also walked Hall in the inning. The right-hander ended the threat by retiring Crawford on a fly to deep center and striking out Julio Lugo with Hall on third base.
- In his previous three outings, Robertson allowed three earned runs in 25 innings while limiting opponents to a .220 batting average.
- Detroit's Carlos Guillen, who has hit safely in nine of 10 games, had the night off.
- Tigers All-Star catcher Ivan Rodriguez sat out for the second straight game with a jammed left pinky.