CHICAGO -- Already in trouble before what they considered a crucial homestand, the Chicago Cubs promptly dropped two of three to the worst team in the major leagues.

"There's only 30-some-odd games left and we're in a big hole, so you can't afford to lose games like this," Derrek Lee said after Thursday's 5-4 loss to the Washington Nationals. "It's been a difficult month. We're not very good right now. We're finding ways to lose rather than finding ways to win."

This time, they fell behind 5-0 and rallied to within a run before Lee was thrown out in the seventh inning while trying to score on a wild pitch that deflected only about 15 feet from home plate.

• Nationals' Morgan breaks hand

With Lee on third and Aramis Ramirez on first, reliever Sean Burnett bounced a 2-2 pitch to Kosuke Fukudome. Catcher Josh Bard scrambled, grabbed the ball and flipped it to Burnett covering home. Replays showed Burnett had the ball in his bare hand and tagged Lee with his empty glove just as Lee's hand reached the plate.

"I just tried to run as fast as I can and throw it toward the plate," Bard said. "I thought when I let the ball go that it was going to hit Fukudome in the back. I couldn't even see Burnett; I just threw it toward home plate. It was a big play."

Washington hasn't gotten many breaks in going 46-82 this season. The Nationals are playing better lately, though, going 14-11 in August and 20-21 since interim manager Jim Riggleman replaced the fired Manny Acta last month.

Ryan Zimmerman hit a two-run homer and Adam Dunn added a solo shot for the Nationals, who won a series at Wrigley Field for the first time since 2005.

It was another demoralizing loss for the Cubs, who have gone 6-15 since Aug. 5 to fall from a first-place tie in the NL Central to nine games behind St. Louis. Even the Cardinals' loss to Houston on Thursday did little to put Chicago in a good mood.

"Look, let's just win some baseball games," manager Lou Piniella said. "Forget the Cardinals and every other team."

J.D. Martin (3-3) outpitched Randy Wells (9-7) to win a matchup of 26-year-old rookie right-handers. Martin allowed three runs and four hits in five innings while Wells gave up five runs and five hits and four walks in 6 1/3 innings.

Mike MacDougal got the final five outs for his 14th save in 15 opportunities. He got Milton Bradley to ground out to end the game with a runner on second.

The hard-throwing MacDougal was in Chicago for the first time since getting dumped by the White Sox in April. He has pitched well for the Nationals, and Riggleman said he has the inside track on the closer job for 2010.

"I'm not thinking about that. I'm just happy getting outs," MacDougal said. "Chicago's a great city; I just don't think it was the right fit for me."

Wells opened the game by walking Nyjer Morgan, who stole second and third and scored on Cristian Guzman's double. After the game, Nationals general manager Mike Rizzo said Morgan broke a bone in his left hand while sliding headfirst into third and wouldn't play again this season.

Zimmerman then lined a home run into the front row of the left-field bleachers. He is batting .340 with 13 homers since the All-Star break.

Guzman's RBI grounder made it 4-0 in the second and Dunn led off the third with his 34th homer.

Ramirez hit a two-run homer in the third and the Cubs closed to 5-3 on Lee's solo shot in the fifth. It was Lee's 25th homer, the sixth time in his career he has hit that many in a season but first time since 2005. Ramirez added an RBI single in the seventh.

Notes

In the fourth inning, Cubs LF Alfonso Soriano's bid for his first HR since July 29 sailed just foul. He then flew out to right. He is batting .118 with three RBI in his past 14 games. ... The announced crowd of 35,174 was the smallest at Wrigley this season. There were thousands of additional empty seats.