Webb became the first Diamondbacks pitcher to open a season 8-0 when he threw his second straight shutout, a 3-0 victory over the Cincinnati Reds on Friday night.
"It's making my job easy," said Melvin, whose only move was inserting Tony Clark as a defensive replacement at first base in the ninth. "I can just sit back and watch. I know he's not going 50-0, but he's on quite the roll."
The sinker-throwing Webb allowed seven hits and induced 17 groundball outs -- seven by shortstop Craig Counsell, including two double plays -- to become the major leagues' first eight-game winner. He beat Atlanta 13-0 on May 20 with a four-hitter.
"Counsell played a great game," Webb said. "Our defense has been awesome. I'm able to relax out there."
Webb, who went into the game leading the NL with an average of one walk per nine innings, matched that and had five strikeouts while earning his 11th win in his last 12 decisions. He was the winner in the Diamondbacks' 7-1 home victory over Cincinnati on May 5.
Randy Johnson started the 2000 season 7-0 for Arizona.
"Brandon Webb did a great job," Reds manager Jerry Narron said. "He gets great late movement, he has that good sinker, and he doesn't give in to the hitters."
"The hitter has to be patient, because he's not going to give you anything in the strike zone," Reds third baseman Edwin Encarnacion said.
Arizona's first run came in the second inning on an error by Encarnacion and Shawn Green added a two-run homer, his fourth, in the ninth.
"It was different when Green hit that homer," Melvin said. "That also made it easy. I didn't have to worry about sending him out there unless some runners got on. It gave us some breathing room."
Cincinnati left-hander Eric Milton (2-2), in his second start since coming off the disabled list on May 20, allowed three hits and one run with a season-high nine strikeouts in eight innings.
The Reds were shut out for the second time in the last five games and fifth time this season. They were shut out eight times last season. Detroit beat them 1-0 last Sunday.
The shutout was the fifth for the Diamondbacks, half of what they had last season.
"I felt good," Milton said. "Webb was a little better. I had to be perfect, and I wasn't. He's on a roll. He's 8-0. We couldn't push across a run. We had some opportunities, but he's tough."
Luiz Gonzalez led off the second with single, moved to third on Green's one-out single and scored on Johnny Estrada's chopper that Encarnacion dropped in his haste to throw home.
"I tried to go home, but it didn't happen," Encarnacion said. "It was tough, but I can make that play."
The Reds got runners to third base with one out three times without scoring or even getting the ball out of the infield. Counsell threw out Austin Kearns at the plate in the fifth with one out to effectively kill Cincinnati's biggest threat.
"The bottom of the lineup was coming up, so I knew he'd try to score," Counsell said. "The ball was hit hard enough that I knew I had enough time."
Ken Griffey Jr. kept the score at 1-0 in the seventh by jumping at the left-center field fence to rob Estrada of a home run. It was Griffey's fourth spectacular catch in Cincinnati's last four games.
- Arizona OF Eric Byrnes extended his season-high hitting streak to 10 games with a single in the sixth.
- Gonzalez needs one double to reach 511 in his career and tie former teammate and current Arizona television broadcaster Mark Grace for 36th place on the career list.
- The Diamondbacks opened a 10-game road trip, tied for their longest of the season.
- The Reds activated LHP Kent Mercker from the 15-day DL and traded OF Cody Ross to Florida for a player to be named or cash.