ARLINGTON -- One thing Joe Nathan is rarely called these days is wild. He probably hasn't heard that in 10 years.
The Texas Rangers' closer entered Tuesday as the leader among major-league relievers in strikeout-to-walk ratio, at 46-to-5. Nathan hadn't walked more than one batter in an inning in 80 straight appearances.
Nathan just doesn't walk many hitters, let alone two in a row with two outs with a game on the line.
But that's what happened against Boston, and that led to a loss in a game the Rangers felt was theirs.
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Mike Aviles lifted a blooper just over Elvis Andrus to score Daniel Nava with the go-ahead run, and Boston walked away with a 2-1 victory to even the three-game series.
Nathan's performance was a stunner after he retired the first two batters on six pitches.
"He pounded the strike zone and got two outs, and then he just couldn't find the strike zone," Rangers manager Ron Washington said. "You've got to give Aviles credit. He reached out there and poked it over the infield. We just couldn't get to it."
The Rangers had to survive a scary moment in the eighth inning, when Adrian Beltre was hit in the head by a 92 mph fastball from Vicente Padilla.
The ball ricocheted high into the air as Beltre went to the ground. He walked toward first base before trainer Jamie Reed stopped him and steered him toward the dugout with an arm around his waist.
The results of an initial concussion exam on Beltre were normal, and he was diagnosed with a head contusion.
Padilla, the former Rangers pitcher with a reputation for throwing at hitters, was ahead in the count 1-2. Despite an apparent lack of intent, the crowd of 41,237 was none too pleased.
"It's a bruise but not as bad as it looked," said Beltre, who was hit behind his left ear near the neck. "It sounded bad when it hit me, but I should be OK.
"I don't know if he was trying to hit me. I don't think in that situation, 1-1, eighth inning, runner at third, he's trying to hit me in that situation. It got away from him."
Padilla (4-0) ended up as the winning pitcher after Nathan's two-out meltdown.
Cody Ross struck out to start the ninth, and Will Middlebrooks chased the first pitch and popped it up to second base.
However, Nava walked on five pitches, and pinch hitter Jarrod Saltalamacchia took a full-count slider for another free pass. The count to Aviles was full when he poked a soft liner over a leaping Andrus.
"Everything was sharp until the Nava [at-bat]; can't walk him," Nathan said. "The at-bat with Salty, he's swinging the bat good. We made sure we were careful. I still like the matchup with Aviles even though we put the guy in scoring position, but the walk to Nava was the one that hurt."
The loss spoiled a nice outing for rookie Martin Perez, who was filling in for Colby Lewis and allowed one run in six innings.
Perez survived a bases-loaded jam in the second inning after Boston collected two soft singles and a walk. Perez was down in the count 3-0 to Aviles but filled the count before getting a fly ball to end the inning.
The first Boston run came with two outs two innings later as Kelly Shoppach, the White Settlement Brewer product, knocked a double off David Murphy's glove in right field to score Ross.
Perez would retire the next six Red Sox hitters and then strand Middlebrooks at second in the sixth after issuing a two-out single and committing a balk.
He was done after 98 pitches on a night the Rangers weren't certain how far he could go.
Ian Kinsler was done after making the first out on a pickoff call he disputed with first-base umpire Tim Tschida. The crew chief ejected Kinsler for arguing, and the Rangers lost their leadoff hitter for the rest of the game.
"I said something I wasn't supposed to say," Kinsler said. "It's that simple."
Jeff Wilson, 817-390-7760