He's 18 innings away - two more shutouts - from breaking Hershiser's record of 59 straight scoreless innings in 1988.
"It's still a ways off," Webb said. "It's going to be real tough to do. I'm just going to go out there and try to throw up zeros as much as I can."
In other NL games, it was Chicago 2, St. Louis 1; New York 6, Washington 2; Houston 3, San Diego 1; Cincinnati 8, Milwaukee 3; Los Angeles 6, Colorado 4; San Francisco 3, Florida 0; and Philadelphia 11, Pittsburgh 8.
Webb (13-8) became the first pitcher since Hershiser to go at least 40 innings without giving up a run and just the 21st pitcher in baseball history to reach that level of stinginess.
"We couldn't hit Webb," Braves manager Bobby Cox said. "I guess nobody can hit Webb. He's that good."
Webb started his streak nearly a month ago. He didn't allow a run in the final inning of his July 20 start against the Chicago Cubs, a 6-2 loss. He's won five in a row since then, going seven innings apiece in wins over Florida and San Diego before beginning his stretch of shutouts with a 3-0 win at the Los Angeles Dodgers.
The only other pitchers since 1940 to have a longer streak than Webb are Don Drysdale (58), Bob Gibson (47) and Sal Maglie (45).
"That's probably the best stuff he's had all year," Arizona manager Bob Melvin said. "To go through that lineup is unbelievable. I really don't know what to say about it."
Chris Young had his second two-homer game of the week. He connected leading off the third against Atlanta starter Lance Cormier (0-3), then added his 24th homer of the season off Tyler Yates in the ninth.
Cormier matched Webb nearly pitch for pitch until the eighth. Conor Jackson singled to center with one out, and Mark Reynolds followed with his 11th homer of the year, driving a 3-1 pitch onto the concourse beyond the center-field seats.
The drive was estimated at 453 feet - the sixth-longest homer in Turner Field history.
Cormier went 7 1-3 innings, allowing eight hits and three runs.
Webb got a bit of a scare in the ninth. Not wanting to walk speedy Willie Harris, he left a pitch over the plate and watched it sail toward deep right.
"I was like, 'Just go right after him. I don't THINK he can hit one out.' And, boom, he got a good piece on it," Webb said. "Luckily, there was the humidity and it's a fairly deep park."
Mets 6, Nationals 2
At Washington, Tom Glavine (11-6) picked up win No. 301 by allowing one run over seven innings to beat the franchise he's beaten more than any other.
Glavine beat the former Montreal Expos for the 33rd time, including the sixth time since the team moved to the nation's capital in 2005. He is 4-1 with a 2.09 ERA in six starts at RFK Stadium.
Damion Easley and Moises Alou homered off Nationals starter Matt Chico (5-7), Jose Reyes stole his 61st and 62nd bases, and Mike DiFelice hit his first triple in three years as the first-place Mets made sure they wouldn't lose ground in the NL East.
