WASHINGTON -- According to Washington right fielder Jayson Werth, the way an intense, September afternoon sun turns fly balls at Nationals Park into adventures "borders on ridiculous."

Well, this time, that "sun monster" helped Werth's Nationals and hurt the Milwaukee Brewers.

A day after the Nationals misplayed a pair of fly balls in the midday glare, Werth wound up with a two-out, two-run double when Brewers center fielder Carlos Gomez lost a ball in the sun to spark a six-run fourth inning Monday, and Washington beat Milwaukee 12-2 to cut its magic number for winning the NL East to five.

"I don't remember a worse sun field, worse sun conditions," said Werth, a major leaguer for a decade. "You almost don't have a chance out there as the game goes on."

Jordan Zimmermann (12-8) allowed one run and four hits in 6 2/3 innings in the rare 1:05 p.m. weekday start. He also delivered two hits and drove in a run as a batter for the Nationals, who are a majors-best 93-60 and increased their division lead over the Atlanta Braves to five games with nine to play.

"We still have a little ways to go, but if we keep playing baseball the way we've been playing, hopefully it'll happen soon," said Ryan Zimmerman, who had three hits and four RBI.

Marco Estrada (4-7) lasted only four innings for the Brewers, who entered the day 2½ games behind the St. Louis Cardinals for the NL's second wild-card berth. He allowed seven runs -- six earned -- and eight hits, and acknowledged that Gomez's problems on Werth's ball into the sun caused the righty to lose his composure "a little bit."

"It felt like it was a blink of an eye," Estrada said. "I looked up, the score was 2-1, and I was like, 'All right, let's get this guy out. Pop fly.' Next thing you know, it's 7-1. I couldn't believe it."

As Brewers manager Ron Roenicke put it: "It would've been a good game if that ball's caught."

Right after Zimmermann's RBI single broke a 1-all tie, Werth hit a high fly that could have been the third out -- but Gomez couldn't find it.

"It is just a matter of being lucky and not getting a ball hit to you when it's in your field of vision," Werth said. "Even then, if the ball is hit to your left early in the game, it goes into the sun. And if it goes to your right later in the game, it goes in the sun. And if it's hit right at you in the middle of the game, you are in trouble."

Gomez paused and held his glove up to try to shade his view, then suddenly scrambled to his left and tried to make a diving catch.

The ball smacked off the dark sweat band on his left forearm and trickled away.

"Nothing you can do," Gomez said.

Roenicke knew his player was having a hard time locating the ball.

"As soon as the ball went up, he was 10 feet off," Roenicke said. "I was watching the ball, where it was, and watching where he was, and I could tell he was off line."

After Bryce Harper walked and joined Werth in a double steal, Zimmerman sent a three-run shot to right-center for his 24th homer and a 7-1 lead.

"Once it gets out of hand, it's tough to keep everybody's intensity there," Roenicke said, "and because of it, a lot of things go wrong."

In Milwaukee's 6-2 victory Sunday, Werth and Harper each failed to catch a ball because of the sun, leading to hits. Werth's misplay was on a shot by Gomez. Afterward, Harper joked about trouble dealing with the "sun monster."

"Payback," said Nationals manager Davey Johnson. "It's a tough sun. I mean, this time of year, that time of day."

Notes

• Nationals SS Ian Desmond stole second in the fifth, giving him 20 steals to go along with 24 homers, making him the team's first 20-20 player since Alfonso Soriano in 2006.
• Brewers 1B Corey Hart hit his 28th homer in the second inning.
• The Nationals will throw three left-handed starters in their next series at Philadelphia, with Ross Detwiler (10-6) on Tuesday, John Lannan (3-0) on Wednesday, and Gio Gonzalez (20-8) on Thursday.
• Washington LF Michael Morse was out of the starting lineup because of a bothersome left hand.
• The Brewers open a three-game series at NL Central champion Cincinnati on Tuesday, with RHPs Mike Fiers (9-8), Shaun Marcum (5-4) and Wily Peralta (2-1) set to start for Milwaukee.
• Harper slammed against the wall in deep center to catch a shot off the bat of Aramis Ramirez to end the first, then rolled onto his back and stayed down for a second or two. Eventually, Harper popped up and jogged to the dugout to loud cheers.