Wilson struck out every Baltimore starter at least once in surpassing his previous career high of 10.
Nick Markakis, the lone left-handed batter in the Baltimore lineup, fanned three times. After the third one, in which all three strikes were called, Markakis animatedly complained to home plate umpire Jeff Nelson and received his first career ejection.
Orioles manager Buck Showalter continued the argument after Markakis left and kept on griping into the ninth, when he was finally ejected by Nelson after a close pitch to Texas' Elvis Andrus was ruled outside the strike zone. It was Showalter's first ejection since he made his debut with Baltimore on Aug. 3.
The defeat dropped the Orioles' record under Showalter to 11-7.
Baltimore starter Jake Arrieta (4-5) gave up two runs, one earned, and eight hits in 6 2/3 innings. The rookie allowed at least one runner in every inning but received aid from catcher Matt Weiters, who threw out a would-be basestealer and picked a runner off second base.
Moreland put the Rangers up 1-0 in the second inning with his third home run, an opposite-field fly to left that carried just inside the foul pole and barely cleared the 7-foot wall.
Texas added an unearned run in the seventh. After shortstop Cesar Izturis mishandled a grounder, Hamilton hit a two-out RBI single off Mark Hendrickson.
In an effort to stack the lineup with right-handed batters and switch-hitters, Showalter started Lugo in left field. It was only the 12th career game in left for Lugo -- the third since 2001 -- and it didn't take long for his inexperience to show.
With two outs in the first, Hamilton hit a rising liner to left that Lugo misjudged and couldn't grab with a late leap. Hamilton got credit for a double to break an 0-for-11 skid, but the Orioles escaped damage when Vladimir Guerrero flied out.
NOTES: Before Moreland's homer, Texas was held scoreless for 25 straight innings at Camden Yards dating to last season. ... Baltimore had won five straight against the Rangers. ... The Orioles' run of three straight starts of at least eight innings ended. ... Wilson came in 1-3 with a 7.15 ERA in 18 career games against Baltimore.