TORONTO - Left-hander Brad Mills pitched a two-hitter over seven innings for his first career major-league victory as the Toronto Blue Jays defeated the Baltimore Orioles 5-0 on Wednesday.

The Blue Jays scored an unearned run in the second and four in the eighth, three on Lyle Overbay's 12th homer, to increase their dominance this season over the Orioles to 12-0.

Mills (1-0) also walked three and struck out four before a crowd of 17,041 at Rogers Centre. The hits, both singles, came from his first batter of the game and his second last.

Orioles starter Jeremy Guthrie (4-11) pitched seven innings, allowing only an unearned run, six hits and an intentional walk while striking out three in seven innings.

Mills was called up from triple-A Las Vegas for the spot start to fill a temporary vacancy in the rotation that resulted from last Friday's rainout in Detroit followed by a make-up doubleheader on Sunday.

He made the first two major-league starts of his career in 2009, both against the Philadelphia Phillies, on June 18 and 26.

The left-hander who prides himself in throwing strikes did not do that in his first chance to pitch in the majors -- he walked six over 7 2-3 innings in the two starts and was 0-1 with a 14.09 earned-run average.

He said he did not throw as many fastballs as usual in those games and generally got away from his game.

Mills was returned on option to Las Vegas where he made one more start, July 2, when he pitched eight runless innings while allowing two hits and one walk while striking out seven.

Then he was sidelined with what was at first diagnosed as a rib fracture that turned out to be a strain. His final triple-A totals were 2-8, 4.06 ERA, in 14 starts.

This year Mills is 7-4 with a 4.13 earned-run average at Las Vegas. Since a stint of the disabled list with a strained left shoulder, he is 3-0 with a 2.00 ERA.

Vernon Wells led off the second with a single. With Wells in motion on a 3-2 pitch, Adam Lind singled to left through the hole left by shortstop Cesar Izturis who moved to cover second. Left-fielder Corey Patterson's error attempting to pick up the ball allowed Wells to score and Lind to take second.

In the eighth, Lind singled against Will Ohman to score Jose Bautista who had doubled against Koji Uehara. Aaron Hill was walked intentionally and Overbay homered.

Notes: The game started with the roof closed because of rain but it was opened in the second inning. ... The Orioles had first baseman Ty Wigginton back for Wednesday's game. He sat out the first two games of the series serving a suspension for bumping umpire Gary Darling on July 22. ... Outfielder Travis Snider hit the game-ending home run Wednesday in the 11th inning as double-A New Hampshire won 1-0 and he will rejoin the Blue Jays on Friday. He has not played for Toronto since May 14 because of a sore wrist that put him on the disabled list. ... Blue Jays have Thursday off before the Cleveland Indians visit Rogers Centre for a three-game series with Justin Masterson (3-9, 5.19 earned-run average) starting in Friday's opener against Shaun Marcum (9-4, 3.36 ERA).