Nate McLouth of the Orioles follows through on his swing for a double in the first inning as Rangers catcher Geovany Soto looks on. (Jim Cowsert/AP)

– In a season of surprises, rookie Miguel Gonzalez may qualify as the biggest one for the Baltimore Orioles, a 29-year-old right-hander signed this February as a minor league free agent.

Gonzalez, who has been in pro ball since 2004 and missed two full seasons because of injuries, hadn’t pitched in the majors before this season yet entered Monday night as one of the best pitchers in the American League in August.

But he couldn’t continue his dominance against the mighty Texas Rangers in a 5-1 loss that was Gonzalez’s worst start since July 25.

Gonzalez (5-3) allowed a baserunner in all five innings he pitched, but it wasn’t until the fourth that the Rangers broke through. The best hitting club in the American League – the Rangers entered Monday with a .276 team average, 32 points higher than the Orioles – scored three runs by stringing together several hole-finding singles.

David Murphy and Geovany Soto each had an RBI hit, and Ian Kinsler added a sacrifice fly in the inning. Nelson Cruz’s RBI double plated the fourth run and helped chase Gonzalez, who was charged with four runs in five innings Monday after giving up three runs in his last three starts combined (21 innings pitched). He had been 2-0 with a 1.29 ERA in three August starts.

Throughout the game Gonzalez struggled with command, walking three (one intentional) and plunking a batter while allowing a career-high eight hits. He was forced to throw 101 pitches in five innings.

The Orioles (66-56) lost for just the third time in eight games, but have now dropped four of five to the AL-West leading Rangers (71-51) this season. In those five contests, the Orioles have been outscored 41-16.

They took an early lead, however, against veteran right-hander Ryan Dempster, who was making his fourth start for Texas after his July 31 trade from the Chicago Cubs.

The only run against Dempster (2-1) could have been charged to the Rangers’ defense. With two outs in the first inning, Nate McLouth hit a ball to right that Cruz misread, jumping about eight feet to the right of where it landed.

After McLouth’s double, Adam Jones followed with a liner that first baseman Mitch Moreland reached with his glove but could not catch. McLouth scored from first on Jones’s team-leading 63rd RBI.

Dempster, who had his start pushed back after he was placed on the restricted list for personal reasons, allowed two baserunners in an inning just once after that. He threw eight superb innings, allowing the lone run on four hits and two walks while fanning six. It was by far his best start for his new club.

Texas closer Joe Nathan struck out the side in the ninth.

Orioles relievers Kevin Gregg and Matt Lindstrom threw perfect innings, but lefty J.C. Romero, in his fourth Orioles’ appearance, allowed a run in the eighth.

— Baltimore Sun