What the Detroit Tigers were hoping would be a very big week in Ohio is off to a very slow start.

With the surprising Tigers' biggest series of the season coming up this weekend, they're not getting much time to turn things around.

The Tigers brought a five-game winning streak and plenty of confidence into a week that's beginning with two games against the last-place Reds in Cincinnati and ending with three against the first-place Indians in Cleveland. They started out the week 2 1/2 games behind the Indians in the AL Central, and were talking openly of leaving Cleveland with the division lead on Sunday night.

But they're now four games back following the Indians' home-field wins over the Chicago White Sox on successive nights and the Tigers' 9-5 loss to the Reds on Tuesday night. The Tigers let their game get away from them in a hurry after Joey Votto hit a grand slam in the third inning off Detroit starter Matthew Boyd (4-5).

The Tigers put up the kind of late-inning outburst that often wins games -- a five-run ninth inning, against Reds reliever Wandy Peralta -- but the trouble was they were down 9-0 when the inning began. Reds starter Sal Romano (4-7) shut them out on four hits over seven innings and now has allowed only one run over 15 innings in his last two starts.

"This wasn't a good game for us," Tigers manager Ron Gardenhire said. "The other guy was throwing the ball well. ... It wasn't one of our better nights. You walk a few people (six), give up a few hits and (have) some long innings, and there you have it."

Now, the Tigers don't have much time to bounce back as they face an afternoon game Wednesday in Great American Ball Park, with right-hander Michael Fulmer (3-5, 4.13 ERA) going up against the Reds' best pitcher of late in Tyler Mahle (5-6, 3.96). The Reds right-hander has permitted only two earned runs over 16 1/3 innings in his last three starts.

"Detroit, you look at their record, they're getting after it every night," said Reds interim manager Jim Riggleman, whose team has won five of seven. "Ron Gardenhire's got them playing hard and you'd better play the whole nine. They're going to come after you."

Neither pitcher in Wednesday's game has faced the opposing team before.

Boyd hadn't seen the Reds before, either, but Cincinnati made quick work of him, chasing him after getting five runs, six hits and three walks off him while he labored through four innings, throwing 80 pitches .

Some of the Reds' low-average hitters did the most damage against Boyd and a Tigers bullpen that was almost flawless during the winning streak. Billy Hamilton, batting .203, went 2-for-4 with a home run and Adam Duvall, batting .196, was 3-for-4. Tucker Barnhart also was 3-for-3 as the Reds collected 13 hits.

Detroit wasted a big night at the plate by leadoff hitter Leonys Martin, who went 3-for-3 with a double and walked twice while reaching base five times.

Mahle got off to a rough start this season, losing six of his first nine decisions, but he pitched 6 1/3 shutout innings against the Kansas City Royals in a 7-0 win last Wednesday and five shutout innings against the San Diego Padres on June 1. In between, he gave up two runs to the Rockies in five innings on June 7.

"It's nice to put a couple (of no-run outings) close together like that," Mahle told reporters after beating the Royals. "I was able to put some zeros up there and our team is always going to be able to score at some point."

Fulmer is coming off a strong start, beating the Minnesota Twins 3-1 on Thursday while giving up only one run on five hits over seven innings. The win was Fulmer's first at Comerica Park in nearly a year, or since July 15.