Oswalt cruised through the first four innings, holding the Rangers to three hits. In the fifth, Texas got to Oswalt, scoring three runs on five hits. Washington was impressed with his first viewing of Oswalt, who made his 11th quality start of the season.
"I thought he was a horse, a little horse," Washington said. "I'm not going to call him a pony, but a little horse. The guy works fast, pounds the strike zone and that's what you want. We made him work today and then we got him a little bit late."
The Rangers were trailing by a run heading into the fifth, when their bats came alive. Ian Kinsler hit an RBI double to score Travis Metcalf. Then, Michael Young drove in Kenny Lofton and Kinsler to cap off the three-run inning against Oswalt.
Lofton, who has the best lifetime average against the Astros, went 3-for-3 off Oswalt, and finished one hit shy of the cycle.
"Kenny was perfect today," Washington said. "He was the catalyst."
With a 3-2 lead, the Rangers added four insurance runs. Gerald Laird led off the inning with a solo shot to left field. Young then had a two-run single, scoring Lofton and Brad Wilkerson, followed by a Marlon Byrd RBI single to bring home Kinsler.
Laird made a great defensive play in the top-half of the inning, getting the lead runner out on a sacrifice bunt attempt by Morgan Ensberg.
"Thank God they had a guy bunting who I don't think does a whole lot of bunting," Washington said.
Then, Laird gunned down Ensberg who tried to steal second.
"I take a lot of pride in my defense," Laird said. "I just got an opportunity to throw a guy out."
The four-game winning streak is the longest of the season, and the Rangers set a franchise record with their 11th Interleague victory.
"I've always said if we pitch well, we got a chance," Washington said. "The streak we're on, give credit to the starting pitching."
Rangers starter Jamey Wright had a solid outing, going 5 2/3 innings and allowing three hits and two runs for his first win of the season.
"I'm disappointed it took till June to get [my first victory]," Wright said. "But it's a big step."
Wright began the game with two walks and had six total, but settled down and didn't allow a hit through the first 3 2/3 innings.
"I tried not to overanalyze my mechanics," he said. "I tried to simplify it. Instead of thinking too much, I was just being aggressive. I had a good sinker, decent curveball, so I tried to use those two pitches."
After leading off the game by giving up two walks, Wright got Hunter Pence to ground into a 6-4-3 double play.
"Getting the double play was huge," Laird said. "He made a good pitch. From that inning on, he started rolling."
It was Wright's second victory in 14 career games against the Astros.
"Thanks for bringing that up," Wright joked. "I got one last year, so I need 10 more wins just to get to .500."
Wright continued the recent trend of strong starting pitching performances for the Rangers, who have won seven of their last nine games.
"Pitching is contagious," Wright said. "For a while there, it seemed like the guys were snake-bit -- everything that could go wrong did. Now, we're putting together some good starts and there's a lot more confidence. It's a good feeling."
Washington was happy Wright just matched Oswalt in putting zeroes up on the scoreboard.
"That's what you have to do in this game -- get zeroes," Washington said.
Texas relievers Frank Francisco, C.J. Wilson, Akinori Otsuka and Eric Gagne closed the final 4 1/3 innings, holding Houston scoreless.
"It's nice to be playing better baseball," said Young, who was 2-for-4 with four RBIs. "We're definitely playing better ball, so hopefully it's a sign of things to come."