PHOENIX -- Randy Johnson insists his shoddy start Thursday was a product of rust and not continued poor health.
"I chalk this up hopefully to just coming off the disabled list and not pitching in 18 days," said Johnson, who lasted just three innings.
The Big Unit, who went on the 15-day DL on June 16 retroactive to June 11 with muscle tightness in his buttocks and a sore back, never looked comfortable in his first start in 18 days. He threw most of his 70 pitches thigh-to-chest high with velocity topping out at 94 mph in the first inning and declining thereafter.
"He wasn't as sharp as we've seen this year and his velocity went down in that (third) inning," Arizona manager Bob Melvin said. "Hopefully the next time the endurance will get better. He wasn't as sharp as we've seen but that's to be expected coming off the DL."
The 43-year-old left-hander allowed four runs -- three earned -- and six hits. He struck out two, walked two and hit a batter with a pitch.
"I threw 70 pitches in three innings which is a lot of pitches in a short period of time," Johnson said. "I missed my spots most of the time."
Asked if his back contributed to his troubles, Johnson (4-3) said it was a "lack of execution."
Martin had three hits and scored three runs, and Jeff Kent had three RBI. Randy Wolf (9-6) allowed three runs in six-plus innings for the Dodgers, who took three of four from the Diamondbacks and opened a half-game lead over idle San Diego in the NL West. Arizona trails Los Angeles by one game.
"We like the way we're playing right now," manager Grady Little said.
The Dodgers have taken seven of their first nine from Arizona.
"I don't put a lot of stock in numbers like that," Little said. "But we like it being that way rather than the other way."
Rafael Furcal led off the game with a single and Martin drove a one-out fastball 434 feet onto the concourse above the center-field wall to give the Dodgers a 2-0 lead. Martin's ninth homer of the season came in his first career at-bat against Johnson.
"That pitch to Martin he wanted to elevate and he left it over the middle," catcher Chris Snyder said. "I'm not sure if it set the tone but it's hard coming back when you fall behind early like that."
Kent fouled out before Johnson hit Luis Gonzalez in the thigh and Matt Kemp looped a broken-bat single to right. But second baseman Orlando Hudson made a leaping grab of James Loney's soft line drive to end the inning.
The Big Unit pitched out of trouble in the second, putting runners on first and second with two out before escaping the jam on a couple of popups, but limped noticeably as he left the field.
"It was my leg," Johnson said. "It's all part of it, the nerve in my calf. It's my landing leg. But I'm looking forward to my next start."
The Dodgers added a pair of runs in the third. Kent walked and advanced to second on Gonzalez's groundout. Kemp singled in Kent, went to third when the ball got past center fielder Chris Young and scored on Loney's bloop single to make it 4-0.
Kent added a two-run single in the fourth to extend the Dodgers' lead to 6-0.
Wolf (9-6) gave up four hits, struck out four and walked six. He left after Arizona loaded the bases with no outs in the seventh.
Eric Byrnes hit a two-run single off the mound against Brett Tomko to cut the Dodgers' lead to 9-3. But Tomko retired Augie Ojeda on a line drive to right, Hudson struck out and Conor Jackson flew out to shallow left to end the rally.
"Obviously six walks is not ideal but it was getting more toward where I want to be," Wolf said. "I still have times where I have little lapses but it's something I keep working on and staying on top of and keep making those adjustments. It's going in the better direction."
Hudson hit a two-run double in the ninth but Takashi Saito replaced Tomko and got two outs for his 22nd save in 23 opportunities.
"When you're in the seventh inning and you've got a 9-1 lead you're not looking forward to using your closer," Little said. "But we had to and he did a great job and got us off the field."
- Johnson tipped his cap to a handful of applauding fans behind the Arizona dugout as he hobbled off the field after the third.
- Johnson had been 4-0 with a 1.52 ERA in his last five starts.
- Wolf, who was 3-for-25 entering the game, helped his cause with a pair of singles.