Houston scored four runs in the seventh and may have been able to pile on a few more, but instead, Berkman's test of Dmitri Young's accuracy cost him and the team, as the Astros fell to the Nationals, 7-6, on a rainy, steamy humid day at RFK Stadium.
The Astros sent eight batters to the plate in the seventh as they chipped away at a 7-2 deficit. Mike Lamb and Luke Scott logged consecutive hits to open the inning, and Lamb scored on Eric Munson's ground-rule double.
Pinch-hitter Craig Biggio knocked in Scott with a sacrifice fly to left, and after Chris Burke walked and Hunter Pence struck out, Berkman laced a double just past an outstretched second baseman Ronnie Belliard, scoring Munson.
Carlos Lee sent a grounder toward third, forcing Ryan Zimmerman to backhand the ball behind the base and make a long throw to Young at first. The throw pulled Young off the bag, allowing Lee to reach safely for a base hit. Burke scored on the play, and Berkman, noticing Zimmerman's low throw to Young, attempted to sneak home.
Young's throw arrived to the plate in plenty of time to nab Berkman, ending the rally.
"I saw Zimmerman backhand the ball," Berkman said. "I didn't know if he was going to throw it or not, so I was watching him the whole time. When I saw he was going to throw it, I kept rounding third, and out of the corner of my eye, I saw that the throw was going to be low.
"I couldn't tell where Carlos was, but if he was going to be safe easy, the better play would be to stop and just watch the throw. But I thought there might be a play on Carlos. On top of that, I never even hesitated. I just kept rounding.
"I thought, 'Dmitri's going to have to make a pretty good play to pick up this low throw and then turn around and throw me out at home plate.' He made the play, and it's one of those deals where if you're safe, it looks like a great play, and if you're out, it looks like a bad play."
Berkman said he vaguely remembered third-base coach Doug Mansolino giving him the stop sign.
"I was watching to make sure [Zimmerman] threw the ball, and as I was rounding and when he let it go, I never really looked at Manso," Berkman said. "I was making up my own mind with what I was going to do. I do vaguely remember as I was running past him, him having the stop sign up. It was totally my fault, my decision and it turned out to not be a good one."
Hindsight, of course, is 20-20.
"If I had to do it all over again, I probably would have stopped, but at the time, it seemed like a good, aggressive play and it just didn't work out," Berkman said.
"If the guy makes a slightly errant throw, he's going to be safe," manager Phil Garner said. "It's an aggressive play. It's a hard-nosed play. If it works, it's great."
The other problem in this game was the starting pitching. Jason Jennings dropped to 1-6 on the year after an ineffective five-inning outing during which he allowed seven runs on eight hits.
Jennings' main problem was control. He issued four walks, all of which turned into runs. The righty yielded consecutive two-out walks in the first frame, and the Nationals converted those into runs when Ryan Church and Austin Kearns logged back-to-back doubles.
Jennings walked Young and Kearns in the fifth, and both scored on Ryan Langerhans' three-run homer, giving the Nats a 7-2 lead.
"Obviously, all four walks, all of them scored," Jennings said. "It's something you can't do. You put guys on base and you give up the one big hit and it's a three-run inning. The biggest mistake on my part today was just the control."
Jennings' early struggles might have been attributed to less-than-favorable conditions. A heavy rain began in the first inning, and while it didn't last long, it was enough to make the conditions very slick.
"I think he was struggling a little bit to get a grip on the ball," Garner said. "He kept trying to get some rosin, kept trying to dry his hand off. It just looked like a couple times, he didn't get the ball where he wanted to. Then he couldn't get it over the plate. It ended up costing him."
"I had to change balls a few times," Jennings said. "It was kind of strange. [The rain] had come down really hard for about 30 seconds and then stopped. It's not an excuse. Just make the pitches."
The Astros are 1-5 on the road trip, which began with a three-game sweep by the Cubs in Chicago.
"It's very frustrating," Berkman said. "I think we played three pretty good games here -- competitive games. Offensively today, I thought we did a great job once we got down pretty big early.
"A lot of times on a day game like that, especially two clubs that have been struggling have a tendency to coast along. But we came right back and really made a game of it. The offense at least gave us a chance to tie the game. We just came up short again."
Alyson Footer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.