On Wednesday, they beat Justin Verlander -- after the Detroit ace had looked untouchable for most of the afternoon.
"They are never going to give up," Rays manager Joe Maddon said. "Say what you want about this team, but they play nine hard innings."
Ben Zobrist hit a tiebreaking two-run single in the top of the ninth, and Tampa Bay scored four runs in its final at-bat to beat Verlander and the Tigers, 4-2. Verlander took a one-hitter into the ninth and hadn't allowed a run all season before the Rays broke through.
Verlander allowed a run on a wild pitch, then Evan Longoria tied the game at 2-2 with a single to left on Verlander's 104th and final pitch.
The Tigers (4-1) lost for the first time this season.
"Once a couple guys got on, really the first time I've cranked it up like that -- and lost a little bit of my consistency that I'd had all day," Verlander said. "It's inexcusable. This loss rests solely on my shoulders today."
"We know now what kind of team we have," Shields said. "We don't fear anyone, because if we keep fighting, we'll win more than our share."
For most of the day, Verlander was marvelous. He took a no-hitter into the fifth and had thrown just 81 pitches through eight.
"When you go against Verlander, if you get the ball in between the giant white lines, you've accomplished something. You know he's going to beat you most of the time, but you just hope he makes a mistake and you can take advantage," Jennings said. "Kepp gave us a lot of confidence. We hadn't been doing anything before that, but he got a hit and we got things going from there."
Verlander's final pitch to Longoria was clocked at 100 mph, but the star third baseman was able to hit a sharp single through the left side of the infield, and neither Detroit reliever was able to stop the rally until it was too late.
"I got away from what I'd been doing all day," Verlander said. "I'd been playing to those guys' aggressiveness, getting them out in front on off-speed stuff and then just got away from it there in the ninth for no reason."
Verlander allowed four runs and four hits in 8 1/3 innings. He walked two and struck out seven. Verlander, last year's AL Cy Young and MVP winner, pitched eight scoreless innings against Boston last week. He didn't get the win that day either -- Valverde squandered the lead, although the Tigers did win that game.
Wednesday was Verlander's first regular-season loss since July 15.
"Kepp was the whole key to the inning. If Verlander gets him out, the game's over," Maddon said. "He shuts the door on you in that situation, but getting a hit there made the whole difference. I think, after that, Verlander started to tune up the velocity and he lost a bit of command in the process."
Shields, who finished third in last year's Cy Young voting, allowed an RBI single in the first to Miguel Cabrera. He also balked in a run in the fifth.
Shields bounced back from a shaky first start, when he allowed six runs and nine hits in five innings against the New York Yankees.
The Rays are 4-1 for the first time in franchise history. They beat Rivera in their season opener, part of a three-game sweep of the Yankees. The Tigers were trying to start 5-0 for the first time since 2006, when they won the American League pennant.
Detroit LHP Drew Smyly will make his major league debut Thursday when he takes the mound against Tampa Bay RHP Jeff Niemann. The Tigers announced they will purchase Smyly's contract before his start and designate OF Clete Thomas for assignment. ... Detroit's Andy Dirks doubled in the fifth and scored on the balk by Shields.