"That's the job of the fourth outfielder, I guess," said Salazar, who was filling in for sore-legged Eric Byrnes. "On this team, those other guys are going to play just about every day. And if they have little aches and pains here or there, or they just need a little breather, my job is to do more than just fill in. I'm going to try to contribute that day and be productive."
Conor Jackson also had a pair of RBIs, helping the Diamondbacks maintain their six-game lead over Colorado in the NL West. When they won the division title last season, the never led by more than five.
Edgar Gonzalez (1-1) allowed three runs and seven hits in 5 1-3 innings with two walks and a strikeout. Brandon Lyon pitched a perfect ninth for his sixth save in eight attempts.
Juan Cruz got out of a bases-loaded jam in the Dodgers' seventh, striking out Matt Kemp and retiring pinch-hitter Mark Sweeney on a flyout after hitting his first batter, Andre Ethier.
Still trailing 5-3, Los Angeles got a run closer on Kent's RBI single. The run was unearned because of an error by third baseman Mark Reynolds, whose throw during a rundown struck Rafael Furcal on the helmet as he retreated to second base on Nomar Garciaparra's comebacker to Chad Qualls.
It was only one of several strange plays during the game. In the Arizona eighth, Reynolds hit what appeared to be a double-play grounder to third. But second base umpire Andy Fletcher ruled that Kent had taken Garciaparra's throw off the bag, prompting a long and loud argument from Kent and manager Joe Torre.
"The only thing I stressed to Andy Fletcher was that Jeff didn't have to come off the bag to catch the ball," Torre said. "Unless you're 100 percent sure and it's clear-cut, you can't make that call unless it's really blatant. It's not like a `safe out' call. I just didn't think it was necessary.
"The guy who's out there playing defensively has a pretty good feel for when the ball is in his glove and where his foot is," Torre added. "Jeff's got a lot of passion, and that's how sure he was that he was right."
Both runners advanced on a wild pitch, and Justin Upton hit a sacrifice fly. Kent resumed his argument with Fletcher at the end of the eighth inning after taking his position, and the two had to be separated before Fletcher ejected him and Torre.
"I challenged the call and I got thrown out for it," Kent said. "You all saw it - and I saw it on the replay, too. It's just a shame."
Crew chief Mike Reilly said: "He had a chance (to argue the first time). Then he came out again, and we're not going to let it continue the next inning over the same call."
Chad Billingsley (0-4) got the loss despite a career-high 12 strikeouts. The right-hander allowed five runs, six hits and two walks over six innings.
Billingsley has 29 strikeouts in 16 innings over his last three starts - including nine against the Diamondbacks in a 1-0 loss on April 13 at Phoenix.
The Dodgers tied it 3-all in the fourth with an RBI single by James Loney and a sacrifice fly by Ethier.
Loney, who had a pair of RBI singles in Wednesday's win, was 4-for-9 in the two-game set with Arizona and is hitting .417 overall against Diamondbacks pitching (30-for-72) with three homers and 15 RBIs. He is 7-for-9 lifetime against Gonzalez with four RBIs.
Arizona regained the lead with two runs in the fifth. Chris Young got a broken-bat single and scored on a wild pitch to Orlando Hudson. After a walk to Hudson put runners at the corners, Jackson barely beat the relay throw from Kent on a potential inning-ending double-play grounder to third as Stephen Drew came across the plate for a 5-3 lead.
Salazar gave the Diamondbacks a 3-1 lead, driving Billingsley's 1-1 cutter into the right-field pavilion after a leadoff double by Miguel Montero. Billingsley struck out eight of his next 10 batters.
Notes: Los Angeles optioned rookie 3B Blake DeWitt to Triple-A Las Vegas and promoted RHP Cory Wade from the Vegas club because the Dodgers needed a 12th pitcher to replenish a battered bullpen. Wade, who turns 25 next month, made his big league debut with a hitless ninth after four-plus seasons in the minors. ... Arizona pitcher Micah Owings, who came in 4-for-13 at the plate this season, pinch-hit for Cruz in the seventh and grounded out.