DETROIT — Kris Medlen and the Atlanta Braves were probably due for a rough stretch.
It's happening now for a team that looked like the class of the National League less than two weeks ago.
Medlen allowed a tiebreaking homer to Omar Infante in the fourth inning, and the Braves lost to the Detroit Tigers 7-4 on Saturday.
Atlanta has won only three of seven after its 12-1 start, and Medlen allowed five runs to the Tigers, matching a career worst.
Infante and Jhonny Peralta both hit two-run homers for Detroit.
"Hanging curveball to Peralta — can't give him one there — and that pitch to Omar that was out over the plate," Medlen said. "All the singles they got were just fastballs that were running back over the plate."
Rick Porcello bounced back from a nightmarish start last weekend to pitch into the seventh inning for the Tigers. Infante's homer broke a 3-all tie in the fourth.
Porcello (1-2) allowed three runs in 6 1-3 innings. He didn't make it through the first last Saturday at Los Angeles, when he gave up nine runs to the Angels.
Atlanta's Justin Upton hit his major league-leading 12th homer in the eighth, but Infante doubled home a run in the bottom half and scored to make it 7-4.
Jose Valverde pitched a perfect ninth for his second save since returning to the Tigers earlier in the week.
"They got a couple of runs — gave them a three-run lead in the ninth," Atlanta manager Fredi Gonzalez said. "It's a different game than a one-run lead."
Medlen became a regular starter for the Braves during the last couple months of last season. He was terrific down the stretch in 2012, and it looked as if this year he'd picked up where he left off.
But Peralta opened the scoring with his two-run shot in the second. Atlanta answered the following inning, when Porcello walked Dan Uggla with the bases loaded, allowed another run on Upton's grounder and gave up an RBI single by Freddie Freeman.
The Tigers tied it in the bottom of the third. With men on first and third and one out, Miguel Cabrera hit a grounder up the middle. Shortstop Andrelton Simmons shoveled the ball to second, but Uggla wasn't able to hold on. The play was scored a single, and a run came home.
Infante's homer came on an 0-2 pitch — after Alex Avila drew a two-out walk to keep the fourth inning going.
"I stayed back and waited for a slider or changeup," Infante said. "He threw a fastball and I made a good reaction."
Joaquin Benoit allowed Upton's homer in the eighth, but Detroit came back with a couple insurance runs. Infante's one-out double made it 6-4, and after he stole third, Austin Jackson walked. Cabrera's two-out single to center gave the Tigers a three-run lead.
The Tigers were prepared to let Valverde leave as a free agent after he struggled at the end of last season, but they brought him back on a minor league deal and eventually called him up this week.
He worked a 1-2-3 ninth for a save against Kansas City, and Saturday's appearance was even more impressive.
He struck out B.J. Upton and Juan Francisco to end it.
Medlen (1-3) and fellow starter Paul Maholm were breezing through the early part of the season for the Braves before coming to Detroit. Then Maholm was knocked around in a 10-0 loss to the Tigers on Friday, and Medlen allowed 10 hits in 5 1-3 innings the following afternoon.
NOTES: Cabrera extended his hitting streak to 11 games. ... Atlanta had been 15-0 when hitting at least one homer, but that streak came to an end Saturday. ... Detroit's Doug Fister (3-0) takes the mound Sunday night in the series finale against Atlanta's Mike Minor (3-1).