Coco Crisp clubbed a tiebreaking solo homer in the top of the ninth inning to lift the Oakland Athletics to a 2-1 victory over the Baltimore Orioles in the second test of a three-game set at Camden Yards.
Baltimore starter Chris Tillman struck out nine over eight efficient innings of one-run ball, but was lifted to begin the ninth after throwing 115 pitches.
Darren O'Day (5-3) took over on the mound and was greeted by Crisp, who lifted a 3-1 slider over the high wall in right field to put Oakland in front.
Grant Balfour retired the O's in order in the home half to secure his 32nd save of the season and make a winner out of Jarrod Parker (10-6), who fanned five and allowed just one run on five hits and three walks over eight stellar frames.
Parker has won his last eight decisions and hasn't lost since May 22 at Texas, a span of 16 starts, which is tied for the second-longest unbeaten streak in A's history with Dan Haren, who accomplished the feat from April 13-July 1, 2007.
Jed Lowrie collected two of Oakland's four hits and knocked in the only other run for the A's, who snapped a three-game losing streak to push their lead over Baltimore to three games for the final wild card spot in the AL.
"You always try to take a win like this with you into the next day," A's manager Bob Melvin said. "You come back out tomorrow and try to take a little bit of this confidence you had today with you."
Ryan Flaherty stroked a solo homer to account for Baltimore's offense, as the Orioles lost for the third time in five games.
"A loss always stinks...it's never fun," Tillman said. "What we're looking forward to is tomorrow and getting this series win."
Parker retired the first seven O's in order before Flaherty scorched a 1-1 fastball over the high wall in right field to give Baltimore a 1-0 lead.
Lowrie laced a one-out single in the fourth for Oakland's first hit, but Tillman retired the next six hitters in order before Kurt Suzuki smacked a double to left with one out in the sixth.
Suzuki moved to second on a Crisp groundout before trotting home on Lowrie's two-out double to right to tie the game at 1-1.
Baltimore put runners on first and second with one out in the sixth and then again in the eighth, but Parker pitched out of trouble each time to keep the score locked at 1-1.
Hall-of-Famer Catfish Hunter holds the Oakland record for the longest unbeaten streak in franchise history, going 17 starts without a loss from June 2-Sept. 3, 1973 ... Baltimore finished 0-for-6 with runners in scoring position and left seven men on base ... Oakland improved to 24-16 in one-run games this season.