HOUSTON -- A day after giving Washington a victory with his offensive skills, Roger Bernadina saved a victory with his defense.
Michael Morse was 0 for 4 when he doubled to start the 12th inning and extend his career-high hitting streak to 16 games. He was replaced by pinch runner Cesar Izturis, who was making his first appearance for Washington after being claimed off waivers from Milwaukee on Monday.
Bernadina advanced Izturis to third with a sacrifice bunt. Espinosa's sharp grounder off Mickey Storey (0-1) skipped past the pitcher for a hit that brought Izturis home and gave the Nationals their second straight extra-inning win over Houston.
Houston's Steve Pearce singled off Tyler Clippard in the 12th before Carlos Corporan drew a two-out walk. Bernadina, the center fielder, crashed into the wall while making a diving catch on a ball hit by Brett Wallace to finish off the victory.
"It was sensational," Nationals manager Davey Johnson said of the catch. "I thought the ball at first was going to go out. I saw him disappear from my angle ... and he came out holding the glove high and I said: `This is great, let's get out of here."
The loss dropped the Astros to 0-11 in extra-inning games this season. Washington beat them 5-4 in 11 innings on Monday.
Bernadina said he had the same feeling when he made the catch that he did when he scored the go-ahead run from first on a bunt attempt during which Houston committed two errors in Monday night's victory.
He knew he was going to hit the wall, but figured he had to do it to save the game.
"This game took forever," he said. "I just want to get out of here and whatever it takes to get an out."
For the Astros, who have baseball's worst record, it was another difficult game in a season full of them.
"I stayed on the field with the guys to tell them how much I appreciate all that they have gone through the last couple of nights," Houston manager Brad Mills said. "It's been tough."
Washington pinch hitter Chad Tracy doubled with two outs in the 10th for the only hit by either team in the first two extra innings.
Drew Storen (1-0) retired the last two hitters in the 11th for the win, and Clippard earned his 23rd save.
Johnson raved about the performance of his bullpen over the last two games, but hopes the group will get a break soon.
"They're holding together and doing a great job, but we need a laugher," he said.
Ben Francisco gave Houston an early lead with a two-run homer off Ross Detwiler to the Crawford Boxes in left field in the first inning. The lead was short-lived as Espinosa tied it at 2-all with his two-run shot to right field off Jordan Lyles in the second.
Both pitchers quickly got back on track.
Detwiler set down the next 10 Astros, with Houston's next hit not coming until back-to-back singles by Pearce and Matt Downs with two outs in the fourth inning.
Detwiler retired Brandon Barnes, who was making his major league debut on Tuesday, and allowed just one baserunner -- a walk in the sixth -- after that. He was replaced by Mike Gonzalez for the eighth inning.
Detwiler allowed three hits and two runs with two strikeouts in seven innings.
Lyles was equally effective, retiring the next nine batters he faced after the homer. Jesus Flores broke the streak with a double with two outs in the fifth.
Lyles walked a batter in the sixth and seventh innings, but didn't give up another hit until he was chased by a single by pinch-hitter Jayson Werth to start the eighth.
Lyles yielded three hits and two runs with six strikeouts in seven-plus innings.
Werth, who left Monday night's game with sore legs, was held out of the lineup on Tuesday, but he pinch-hit in the eighth inning. Werth was reinstated last Thursday after missing almost three months with a broken left wrist. ... Houston placed CF Jordan Schafer on the 15-day disabled list with an injured left shoulder on Tuesday. The Astros aren't sure how long he'll be out. "I really have no timetable," Schafer said. "Whenever I feel healthy, whenever I get better, then I'll get back in there." Houston purchased the contract of Barnes to take Schafer's spot on the roster.