ARLINGTON -- From the start, Rangers starter Sidney Ponson knew it wasn't going to be his day against the Athletics. And it certainly wasn't a good day for reliever Eddie Guardado. In fact, it wasn't a good day for the Rangers in general, considering that ace Kevin Millwood was placed on the 15-day disabled list prior to the game.

In the end, the Rangers fell to Oakland, 12-6, on Mother's Day at Rangers Ballpark in Arlington. The loss snapped the Rangers five-game winning streak as they were unable to complete their first three-game sweep of the season.

Ponson struggled from the start. He hit the second batter he faced, then gave up four runs and four hits in the first inning, including a three-run home run to Oakland left fielder Emil Brown.

"I wanted to go down and right and it's in the middle of the plate like a souvenir," Ponson said. "They're professional hitters and know what to do.

"My stuff was off. I didn't have any command on anything, so I tried to mix up my pitches. It's one of those days. You just have to tip your hat to them."

Still, Ponson battled and held Oakland scoreless after the first inning until the sixth, when he issued two walks to Jack Hannahan and Ryan Sweeney. Eventually, both would score and Ponson's day was finished after 5 1/3 innings, allowing a season-high six runs (all earned) on seven hits.

It was a shorter outing than the Rangers were hoping for, though, especially a day after the bullpen had to go 8 1/3 innings to compensate for Millwood's injury.

Following Sunday's 3 2/3 innings pitched, the Rangers' bullpen has now thrown the most innings -- 136 2/3 -- of any team in the American League. Manager Ron Washington, however, isn't concerned about that.

"Yesterday was a freak game and we had to fight through today," Washington said. "Give credit to the Oakland Athletics. We'll be fine. We will have four or five relievers available tomorrow. It happens to every ballclub. We'll be fine."

Despite trailing 4-0 after the first, though, the Rangers responded. In the first, Josh Hamilton and Milton Bradley had back-to-back two-out doubles to score a run. The Rangers tacked on one more in the second on Ian Kinsler's single to center. Jarrod Saltalamacchia drove in two more runs in the third and Hamilton added to his Major League-leading RBI total with a run-scoring triple to right in the fourth.

The Rangers had the lead after four innings, 5-4, and even knocked Oakland starter Rich Harden out of the game in the fourth, after scoring five runs on eight hits while drawing four walks.

The Athletics retook the lead in the sixth, however, when Ponson walked the first two batters -- Hannahan and Sweeney -- and both would score. The Rangers tied it in the sixth on Michael Young's RBI double, but that was the only run they would score against Oakland's bullpen over the final five innings.

"We battled back and came back swinging well," Young said. "I have faith in our ability, but we just didn't score enough."

Oakland ran away with the game late. The Athletics scored two runs in the seventh and one in the eighth. The A's cushioned their lead in the ninth, when Daric Barton had a two-run blast to right field off Guardado.

"It's just one of those days," Guardado said. "It didn't work out and it especially didn't work out for me today. But we'll be fine. We won the series and that's what you need to do."

Despite the loss, the Rangers did win the series, their fifth consecutive one. It's the first time the Rangers have reached that mark since Aug. 23-Sept. 7, 2005.

"We fought and came back and we'll bounce back," Washington said. "I would've liked to win the third one, but we want to win series. I still feel good about this team."