The D-backs were seemingly on their way to a win that would have allowed them to capture their first series at Dodger Stadium in nearly three years.
Yet it slipped away.
The D-backs rolled through the game's first five innings behind the right arm of Dan Haren, who kept the Dodgers off the board while his teammates managed to push across three runs.
Haren finally seemed to tire in the seventh and with one out, a runner on first and his pitch count at 121, Hinch decided that was enough and went to Aaron Heilman.
"He gave us everything he had," D-backs manager A.J. Hinch said of Haren. "We squeezed every last pitch out of him that we could. He was tiring at the end, but I thought he battled well."
Matt Kemp greeted Heilman by launching a 1-1 fastball that caught too much of the plate over the wall in center to tie the game.
"I just made a mistake, left it out over the middle of the plate and he was able to put a good swing on it," Heilman said. "We had this game won. It's a game we should have won. I made the mistake and let them get back in the game. Danny pitched a phenomenal game. This one kind of stings a little bit."
As they've done so far in the young season, though, the D-backs continued to battle.
Justin Upton hit a mammoth homer to left to lead off the eighth and the D-backs managed to push across one run in the ninth against George Sherrill to go on top, 5-3. They would, however, leave the bases loaded in the inning -- something that would prove costly.
Chad Qualls came on to try and save things for the D-backs, but for the second straight night he was unable to do so.
"He was one pitch away from being done and him saving the game," Hinch said.
A two-out single by Manny Ramirez scored Rafael Furcal and brought the Dodgers to within 5-4.
A James Loney single put runners at first and second before Casey Blake hit a tapper to short. Stephen Drew charged the ball and fielded it nicely on a short hop. His throw to first, though, sailed over the first-base dugout, allowing Ramirez to score with the game-tying run.
Had the throw been on target, it looked as though it would have been a bang-bang play at first.
"It was a tough play," Drew said. "It was do-or-die, and it was one of those things where I didn't really have a good grip, and with the mist on the ball I threw it away.
"Normally I make those plays. If I get a good grip on that ball, I think I've got a shot to get him out and that ends the game. If I had to do it over again, I'd do it again, that's just how I am. It's just one of those things where it's frustrating. I'm not going to make excuses. I threw it away."
The 10th inning was no better for the D-backs. Blaine Boyer allowed a single to start the inning, and after a sacrifice bunt by Furcal, Kemp was walked intentionally to set up a possible double play.
That went by the boards quickly, though, when Boyer's first pitch to Andre Ethier got by John Hester for a passed ball that allowed the runners to move to second and third.
After running the count to 2-1, Ethier smoked a slider over Chris Young's head in center as the winning run crossed the plate.
It was the 10th career walk-off hit for Ethier, who had six game-enders in 2009.
"To lose like that is tough," Hinch said. "It's a tough blow. It's a game that we feel like we should have won and were in a position to win with our best pitchers on the mound. So to lose it like that is tough. At the end of the day, they made the plays when they needed to."