PHOENIX -- Facing Merrill Kelly for the third time in the last three weeks, the Giants seemingly had an advantage based on familiarity with him.

Yeah, not so much.

Kelly allowed just three hits over eight innings as the D-backs rolled past the Giants, 7-0, on Monday night at Chase Field.

"I think the way he just mixes his pitches and his locations," Giants outfielder Luis González said. "There's very few mistakes on his part. We don't really get much to hit. His changeup is a very good pitch to a lefty. I think we've just been struggling on sitting back on it and driving that pitch."

In those three starts against the Giants, Kelly has worked 21 1/3 innings and allowed just four runs, good for a 1.69 ERA.

Monday, he was perfect through the first five innings before González doubled down the right-field line to open the sixth. The only other two San Francisco runners to reach base did so via bunt hits.

"Merrill did a tremendous job," D-backs catcher Carson Kelly said. "He was in command of all his pitches. It seemed like he had a little bit more giddy-up on a lot of his pitches today. We attacked, didn't waste any time and got a lot of weak contact early. It seemed like he was ahead of almost every hitter, so when a pitcher is doing that, it makes my job easier and definitely puts us in a good position to win that ballgame."

By the time the eighth inning rolled around, the D-backs were already up 5-0 and the biggest question at that point was whether Merrill Kelly would notch his first complete game.

Sitting at 87 pitches to start the eighth, it seemed possible, but after a 12-pitch eighth, D-backs manager Torey Lovullo elected not to send him back out for the ninth.

The reason Lovullo decided against pushing Kelly's pitch count any further can be traced back to May 6 when Lovullo decided to let Kelly try to finish off a complete game against the Rockies. Kelly came up one out shy of the complete game throwing 106 pitches, but it was what happened after that was the issue.

"Take a look at what happened last time we ran Merrill into that 110-ish area in his following three starts," Lovullo said. "So I want to protect him while he's throwing the ball really well."

In his five starts right after the Rockies game, Kelly did not last past the fifth inning in any of the starts and had a 7.77 ERA.

Kelly lobbied hard to stay in the Rockies game, but this time around, he was not.

"Do I think I could have?" Kelly said of pitching the ninth. "Probably. Was I OK today with not? Yeah, it's a 5-0 lead, kind of sneaky sweaty out there today. I ran out of gas a little bit out there."

Over his last five starts, Kelly has a 1.57 ERA and he's pitching with a confidence that is noticeable from the opposing dugout.

"He had excellent command today," Giants manager Gabe Kapler said. "He really commanded glove side, and it was keeping both our right-handed and left-handed hitters off-balance and unable to get their best swings off. He just wasn't in the middle of the plate very often, he was all over the corners and he mixed his pitches well. He worked fast, efficiently and with a ton of confidence."

And as for that complete game?

"There's definitely not as many complete games going around as there used to be but it's definitely something that I want at some point," Kelly said. "It just has to be in the right situation."

Monday wasn't that situation, but the way he's throwing right now, it could come soon.