Pena hit a three-run homer in a seven-run first inning, and the Tigers beat the Toronto Blue Jays 17-6 Sunday to extend their winning streak to four.
"We haven't had too many of these games lately," Detroit manager Alan Trammell said. "Carlos comes out right from the get-go with a home run, and it seemed to kind of snowball from there."
It was the most runs for the Tigers since a 17-3 win over Cleveland on April 23, 2004, and Detroit had 15 hits to reach double digits for the third straight game. The Tigers, who have won seven of eight, won three straight over Toronto for their first sweep since taking three games from San Diego from June 14-16.
The sweep was the Tigers' first of Toronto in Detroit since the last week of the 1987 season, when the Detroit won the AL East title. Last week, the Tigers won a series against the Boston Red Sox.
"When you win two out of three against the world champions, you feel like you can beat any team in the league," said Brandon Inge, who had three hits and three RBIs.
Toronto, which had won three-game series in Baltimore and Anaheim before coming to Detroit, dropped to 4-5 on a 13-game trip.
"We ran into a good-hitting ballclub," Blue Jays manager John Gibbons said. "I guess you can say it was the 'Motor City Mauling.' Now we'll go to Yankee Stadium, and that place can rejuvenate you. The final leg of this trip isn't easy."
Sean Douglass (5-2), who appeared in 14 games for Toronto last season, gave up four runs and eight hits in 6 1/3 innings. He took a shutout into the seventh, when he allowed a solo homer by Corey Koskie and a two-run drive by Eric Hinske.
"The way he's been pitching lately, we almost feel obligated to go out there and get him some runs," Inge said. "Confidence is the key in baseball. When you feel confident, you're going to put up good numbers."
Douglass threw 106 pitches, his most this season.
"He only had 95 going into the inning, and we were hoping he would go seven," Trammell said. "It didn't happen, but he still was great for us."
Toronto rookie Dustin McGowan (1-1) allowed 12 runs -- 10 earned -- nine hits, three hit batters and two walks in 4 1/3 innings. He lost for the first time in five career starts, and his season ERA rose from 5.95 to 8.63.
"This was a pretty important game to give the bullpen a rest after last night's game," McGowan said, referring to Detroit's 3-2, 13-inning win. "Hopefully, one day I can put this one behind me."
Ken Huckaby doubled down the right-field line in the ninth and Monroe tossed it into the stands as Huckaby came home. Huckaby was given a double, and Monroe was charged with an error.
"I thought it was a foul ball," Monroe said. "But with 17 runs on the board, I'll take it."
- Toronto had not allowed a home run in 55 straight innings coming into the series. The Blue Jays gave up 10 to the Tigers.
- Gibbons said LHP Ted Lilly (left biceps tendinitis), out since July 25, could begin a rehab assignment later this week.
- Rock star Alice Cooper, a native of suburban Ann Arbor, threw out the ceremonial first pitch.