PHOENIX – The Arizona Diamondbacks are alone atop the NL West for the first time since April 30.

Stephen Drew and Chad Tracy homered, Eric Byrnes drove in two runs and the Diamondbacks defeated the Baltimore Orioles 8-3 on Sunday for their seventh victory in nine games.

The victory, coupled with San Diego’s 4-2 loss to Boston, gave Arizona a one-game lead over the Padres. The Diamondbacks have a 11/2-game edge over the Los Angeles Dodgers, who come to town for a four-game series beginning Monday.

The Diamondbacks built an early lead and coasted behind Doug Davis (5-8), who allowed two runs and 10 hits in 6 1-3 innings. He walked two and struck out three.

Davis, who is hitting .083 (2-for-24), also singled in a run as he won for only the third time in 11 starts.

Brandon Lyon escaped a bases-loaded, one-out jam in the ninth.

Brian Roberts homered and had four hits for the Orioles, who have lost 16 of 21 games. Roberts went 7-for-13 with five RBIs, two triples and two homers in the three-game series.

Melvin Mora hit his 11th homer, a solo shot to the home bullpen in left field, in the eighth off Arizona reliever Jailen Peguero.

Arizona jumped on Baltimore starter Steve Trachsel (5-6). With one out in the first, Drew hit a 1-2 delivery into the visitors’ bullpen down the right-field line for his fourth homer.

In the second, Chris Young tripled and scored on Carlos Quentin’s sacrifice fly.

Arizona made it 5-0 in the fourth on RBI singles by Davis and Byrnes, and a sacrifice fly by Orlando Hudson. Byrnes singled home another run in the fifth, and Mark Reynolds hit a sacrifice fly in the sixth.

Trachsel allowed five runs and seven hits in four innings. He walked four and struck out three. Eleven of the 23 batters he faced reached base.

Tracy hit a solo homer in the eighth off Baltimore’s Chris Ray.

Notes: Davis, who last week snapped an 0-for-51 slump at the plate, has a two-game hitting streak. He singled through a drawn-in infield. … Roberts went 14-for-25 with six extra-base hits on the Orioles’ six-game swing through San Diego and Arizona. … The last time the Diamondbacks had sole possession of first place was after a 9-1 victory over the Dodgers on April 30. Arizona dropped its next five games.

AP-ES-06-24-07 2010EDT