Shields remained undefeated, pitching seven strong innings and the Devil Rays beat the Florida Marlins 7-2 on Saturday night.
Shields (6-0) has emerged as the Devil Rays' most consistent pitcher in his second year as a starter. The 25-year-old right-hander allowed six hits and struck out nine in winning his third straight start.
It was the ninth time in his last 10 starts that Shields has held the opposition to three runs or fewer.
"When he's on the mound, our guys feel like they have a real chance to win," Rays Manager Joe Maddon said. "When you look at the more successful clubs, they have a few guys like that, and that's the direction we want to be headed."
Dontrelle Willis (7-5) took the loss, allowing four runs and eight hits while striking out five in seven innings.
Navarro spent several hours in the hospital but was released and in uniform for Saturday's game. He is expected to return to the lineup on Tuesday.
The Devil Rays tagged Willis for four runs in the second, making the most of four infield hits.
Delmon Young's infield single drove in Iwamura for the first run.
Elijah Dukes delivered another infield single that scored Harris, and Wigginton came home on Hanley Ramirez's throwing error to first. Jorge Cantu's sharp single to left -- the Rays' only hit to leave the infield that inning -- scored Young to make it 4-0.
That was all the support Shields needed.
"I've been making my pitches, and when you do that and go deep into the game, it makes a difference," he said.
"This is still a learning experience, and every time I go out there I want to take something from the start and hopefully build on it."
Gary Glover pitched two scoreless innings in relief of Shields.
Miguel Cabrera hit his 13th home run, a two-run shot in the sixth that cut the lead to 4-2.
The Marlins had runners on first and second with none out in the seventh, but Shields pitched out of trouble, striking out pinch-hitter Jason Wood and Alfredo Amezaga, and retiring Dan Uggla on a fly ball.
Willis pitched well, but fell victim to some bad fortune in the third as the Devil Rays patched together four infield hits en route to the four runs.
"There's nothing you can do about that," Willis said. "You walk away from it knowing that it just wasn't your day. Guys were diving after balls and trying to get them, and in most situations we make those plays. They just happened to put enough wood on the ball to hit them where our guys weren't."
Marlins manager Fredi Gonzalez reasoned that Willis had the kind of night that balances out over 35 starts. There are nights when Willis might not pitch that well but benefit from strong run support, Gonzalez said.
"He pitched a lot better than his linescore will show," Gonzalez said. "That's baseball. It's a 35-start season for him. He's going to have games where he doesn't pitch that well and then have his team give him 10 runs."
- The Devil Rays defeated Florida for the first time in five meetings this year. It was only the fifth win for Tampa Bay against Florida in the last 18 games between the teams.
- The Marlins were looking to climb above .500 for the first time since being 6-5 on April 15.
- Dukes snapped an 0-for-24 slump with an infield hit in the second.
- Shields has pitched into the seventh inning in all 13 starts this year.
- Casanova handled the catching duties for the Devil Rays, who have no other catcher on their roster. Ty Wigginton is the emergency catcher until Navarro returns to the lineup.
- Willis has just two wins in his last eight starts.