Doug Davis (13-11) allowed one run in seven innings as he reached a career high in victories. Davis gave up six hits and five walks and struck out five.
Acquired from Milwaukee in the offseason, Davis started his stint in the desert 2-6. He's been a different pitcher over the last two months, winning eight of his last nine decisions.
"He's been huge for us down the stretch," Clark said. "He's simply doing what he's capable of doing."
While Davis cruised, Young (9-6) continued to struggle since coming off the disabled list with a strained left oblique muscle. He has allowed 14 earned runs in his last 13 1/3 innings, a span of three starts.
No one hits Young harder than the Diamondbacks. Three of Young's six losses have come against Arizona, and he has allowed 16 earned runs in 19 2/3 innings, a 7.32 ERA.
Young is 9-3 with a 1.88 ERA against everyone else.
"You look at his numbers across the board, he's one of the better pitchers in the league," Arizona manager Bob Melvin said. "So we're fortunate to get some success off him."
No Diamondback hits Young harder than Clark, who is 4-for-9 with four homers against him.
"Maybe it's the tall-tall thing," Melvin said, referring to the 6-foot-7 Clark and the 6-foot-10 Young, both of whom played college basketball.
Clark seemed mystified by his numbers against Young.
"I don't know, nor am I going to try to figure it out," Clark said. "He is an uncomfortable at-bat. Very rarely do you face somebody who's at least an inch taller than I am."
Young walked six Diamondbacks in his last start, and he again struggled with his control, throwing nine of his first 10 pitches for balls. After walking Stephen Drew and Orlando Hudson, Young got Byrnes to ground into a 6-4-3 double play, sending Drew to third.
That brought up Clark, who hit a 2-1 pitch 438 feet to dead center to put the Diamondbacks ahead 2-0.
In the third, Young gave up a one-out double to Drew and a bunt single to Hudson before Byrnes hit a 3-2 pitch into the left-center field seats to make it 5-0.
Young left after four innings, giving up five runs and four hits. He walked two and struck out six.
"I felt better, a little better, still not where I need to be," Young said. "I'm a little discouraged by that, but I can't expect to miss too much time, the way my last month has been, and come back and be as sharp as I was before."
While Young struggled, Davis cruised. As is customary, he allowed a baserunner in every inning but worked out of trouble.
"We had some chances," San Diego manager Bud Black said. "We had Davis on the ropes. Couldn't quite deliver like we did last night" in a 10-2 win.
Hudson had three hits and stole two bases for Arizona.
- San Diego LF Bradley was ejected by plate umpire Phil Cuzzi after being called out on strikes in the fifth.
- The Padres caught slow-footed Arizona C Chris Snyder stealing second in the eighth, snapping a streak of 32 consecutive steals allowed.
- Padres RHP Jake Peavy will start the series finale on three days' rest on Wednesday night.
- Arizona CF Chris Young fouled out and struck out and is 0-for-10 lifetime against San Diego RHP Chris Young.