With three games remaining in April, Chicago matched a franchise mark with its 16th win in the month. The Cubs, whose 16-8 record equals their 1995 start, needed a deep outing from Zambrano to protect a spent bullpen and snap a two-game skid.
"Zambrano's a wonder. We needed seven or eight innings from him, and that's exactly what we got," Chicago manager Lou Piniella said. "We needed to swing the bats a little bit, and we did."
Zambrano (4-1) walked four and struck out five to improve to 86-56 for his career. Since entering Chicago's rotation for good on July 1, 2002, his 45 road victories rank second in the major leagues behind Johan Santana's 48.
"The offense came out and gave me a big game. ... That's how we play the game," Zambrano said. "We pick each other up and we play as a team. When you play as a team, you're going to have a good game."
The right-hander, who has pitched seven innings in each of his four victories this year, improved to 6-2 lifetime against the Nationals. He had to work out of a jam in the seventh, striking out Ryan Zimmerman on a 3-2 breaking pitch with runners on second and third before thrusting his right arm in the air.
"When you feel good and have good stuff and you walk people, that's how you get out of the situation," Zambrano said.
The Cubs pounded out 13 hits and improved to 14-0 when scoring four or more runs.
"Last year, we got off to a slow start, and that's tough to overcome," said Chicago third baseman Aramis Ramirez. "We did it last year; we don't want to want to be in that position again. We're doing everything right. We're hitting and we're pitching pretty good."
A three-run first inning helped the Cubs avert their first three-game skid of the season. After Reed Johnson and Ryan Theriot singled, Lee hit a run-scoring single to left off Matt Chico (0-5). Kosuke Fukudome drew a one-out walk and Mark DeRosa slapped a two-run single to left.
The top of the order and Lee delivered again in the second. Following one-out singles by Johnson and Theriot, Lee ripped a two-run double into the left-field corner for a 5-0 lead.
"It was kind of tough playing catch-up baseball against Zambrano right off the bat. ... It was early, and we had plenty of innings and opportunities to get back into the game," Nationals manager Manny Acta said. "But that's why he is who he is and we just couldn't do much against him."
Ramirez added a two-run double off Jesus Colome in the eighth.
Chico, whose seven victories were the most by a rookie left-handed starter last season, continues to search for his first win of 2008. He allowed five runs on eight hits, walked two and struck out five.
"I thought I got the groundballs that I needed, but they were just out of the reach of everybody. I couldn't buy a break. ... I think I'm trying to do a little too much right now," he said. "I just got to settle down and go and let everything happen. It's trying to get out of the rut I'm in."
Cubs C Geovany Soto struck out five times, each time against a different Washington pitcher. ... The Nationals matched a season high with 12 strikeouts. ... Piniella moved into sole possession of 14th place on the career managerial wins list with 1,620 victories. ...Fukudome celebrated his 31st birthday and was presented with a cake from the Japanese media covering the Cubs.