WASHINGTON -- Livan Hernandez doesn't expect a minor leg injury to get in the way of his impressive streak.
Hernandez (6-2) pitched 6 1/3 innings before leaving because of soreness in his right knee. He allowed two runs and five hits, walked none and struck out six -- all after enduring a lengthy rain delay at the start of the game.
"I'll be all right," Hernandez said, adding that he hurt the back of his leg in his last start in Arizona. "I pitched today, so maybe I'll pitch better and better."
It is Hernandez's longest streak since winning six straight starts from June 28-Aug. 4, 1997, his rookie year with the Florida Marlins.
"He gutted it out as long as he could," Nationals manager Frank Robinson said. "I certainly appreciate that."
Chicago had a three-game winning streak snapped and the Nationals halted a three-game skid.
"My guys battled back. We had action," Cubs manager Dusty Baker said. "Boy, it's hard coming up short like this."
Gary Majewski pitched 1 2/3 scoreless innings in relief of Hernandez, and Chad Cordero allowed Corey Patterson's RBI single in the ninth before getting his eighth save in 10 chances.
The start of the game was delayed for 2 hours, 40 minutes by severe thunderstorms, lightning and heavy rain. When play was finally ready to resume, Cubs leadoff hitter Patterson had to wait an extra two minutes for the gate in the center-field wall to be closed.
During the torrential downpour, gusty wind blew the large metal tube on which the tarp is rolled from the warning track in left-center field into short right-center field, a distance of about 200 feet, with the crowd cheering its progress.
The Cubs appeared to complain about the condition of their bullpen, and starting pitcher Carlos Zambrano's warmups were delayed until additional drying compound could be applied to mound.
In previous games, the RFK Stadium grounds crew struggled to get the tarp down during storms and large puddles appeared in the infield. This time, the grounds crew drew praise.
"It looked worse than it was," Robinson said. "Once they took the tarp off and fixed the field, it was good."
Zambrano (3-2) helped himself to a 1-0 lead in the second, doubling with two outs for the Cubs' first hit and scoring on Patterson's ground-rule double.
Zambrano retired his first nine batters before running into trouble in the fourth and eventually leaving the game with what trainer Mark O'Neal called "tennis elbow." Baker said Zambrano will be re-evaluated Sunday.
Washington sent nine men to the plate in the fourth and went ahead 4-1. The Nationals loaded the bases with one out before a two-run single by Castilla, who snapped a 3-for-24 slump, then increased the lead on RBI singles by Ryan Church and Cristian Guzman.
"That's what we've been missing," Robinson said. "We're only getting one (big) hit. Tonight we got the second and third hits. ... Instead of scoring one run, we scored four."
Pinch-hitter Jose Macias' run-scoring single got Chicago to 4-2 in the fifth.