After winning the series opener on Monday the Orioles put themselves into position to claim their first series since taking two of three from Cincinnati from June 24-26. However, they couldn't deliver on Tuesday, as Guillermo Moscoso had a quality start and Oakland got plenty of offense to roll to an 8-4 win.
Moscoso (6-6) was charged with three runs -- two earned -- on five hits over six full frames.
Brian Matusz (1-5), in his first big-league start since June 30, was touched for six runs on eight hits in 6 2/3 innings for Baltimore, which was denied its third straight win.
"I thought [Matusz] deserved a lot better than what the line may read," Orioles manager Buck Showalter said.
Heading to the hill for the A's today will be righty Brandon McCarthy, who lost for the first time in five decisions on Friday. McCarthy couldn't get out of the fourth inning of that one against Texas, surrendering seven runs (five earned) and eight hits in just 3 1/3 frames. He is 5-6 on the year with a 3.62 ERA.
McCarthy has faced the Orioles six times (four starts) and is 0-1 with a 4.70 ERA.
Baltimore, meanwhile, will counter with righty Alfredo Simon, who is 3-5 with a 4.35 ERA. Simon did not get a decision against the Detroit Tigers on Friday, as he allowed four runs and 11 hits in 4 2/3 innings of a 5-4 loss.
Simon lost to the A's in a relief effort earlier in the year and has pitched to an 11.57 ERA in three appearances against them out of the bullpen.
The O's have split their eight matchups with the A's this season after dropping seven of the 10 matchups in the season series a year ago. A win today would also give Baltimore its first season-series win over the A's since 1998.