PHOENIX -- Since taking over as Arizona's manager last season, Kirk Gibson has repeatedly given his hitters the green light on 3-0 counts, hoping it would make them comfortable whenever the situation arises.

Sometimes it's worked, a lot of times it hasn't.

Justin Upton got it to work in a big way.

Swinging on 3-0 in a tie game, Upton led off the eighth inning with a home run to right field, lifting the Arizona Diamondbacks to a 4-3 victory against the Colorado Rockies on Tuesday night.

"For J-Up to go [opposite field] like that, it's a good approach, and it was a game-winner," Gibson said. "That's one of the times where it's paid off when we've done it."

Joe Saunders gave Arizona a decent start for the first time at home this season and David Hernandez (1-0) worked out of a jam in the eighth inning. Most of the offense came in the third, when Henry Blanco hit his first home run in nearly a year and Xavier Nady had a two-run single to prevent Jorge De La Rosa from becoming the NL's first five-game winner.

All that set up Upton.

In a good power groove to start the season, Upton took his usual don't-do-too-much approach on a 3-0 count, using an inside-out swing against Felipe Paulino (0-1) to lift the ball just over the wall in right for his sixth home run. J.J. Putz followed by finishing off the ninth with his seventh successful save opportunity to open the season, giving the Diamondbacks their fifth victory in eight games.

"I wasn't trying to do too much," Upton said. "Just make sure it's a strike and don't come out of your shoes, and I was able to get a good pitch to hit."

Colorado had its chances.

De La Rosa was solid after the third inning, Carlos Gonzalez hit a mammoth home run against Saunders and Jonathan Herrera had a run-scoring triple off him.

The Rockies just couldn't come through when they needed to, failing to score in the eighth with a runner on third and one out while finishing 0 for 6 with runners in scoring position.

"We had a wonderful opportunity in the eighth inning and we weren't able to get a hit there," Rockies manager Jim Tracy said. "That is where the game lies. Our chances were there. We just couldn't get a big hit."

De La Rosa had a strong previous outing, striking out nine while allowing a run in seven innings against the Cubs.

He had more trouble than that just in the third inning against the Diamondbacks.

Blanco led it off with his first hit in 11 at-bats this season, sending the left-hander's first pitch to the back of the lower level in left. It was his first home run since June 10 last season against San Diego, a span of 90 at-bats.

Saunders followed with his first hit in nine at-bats this season, a slap single to left, then De La Rosa struggled with the strike zone, walking two batters to load the bases. Nady capped the inning with a two-run single up the middle, putting the Diamondbacks up 3-1.

"I was making mistakes with most hitters and I paid for it," said De La Rosa, who allowed three runs on seven hits in six innings.

Saunders just couldn't hold the lead.

The left-hander gave up his first run on Ryan Spilborghs' sacrifice fly in the second inning and followed Arizona's big inning by giving up a leadoff home run to Gonzalez, an estimated 453-foot shot that landed behind the pool in right-center. Herrera tied it in the fifth with a run-scoring triple to the corner in right.

Saunders didn't give up anything else, though, leaving with the score tied after allowing three runs on six hits in six innings. He didn't get the victory, but after going 0-2 with an 8.82 ERA in three previous starts at Chase Field, it was at least an improvement.

"I didn't feel like I had my best command or stuff, but we fought through it," said Saunders, who ended an 0-for-18 streak over two seasons with his single in the third. "Got through six and gave us a chance to win the game."

Notes

The final out of Francisco Liriano's no-hitter for Minnesota was shown on the video screen before the start of the third inning, drawing a smattering of applause from the fans. ... Saunders has yet to get to the seventh inning in six starts this season. ... The Rockies have hit more home runs against left-handed pitchers (12) than any other NL team this season. Arizona is second with 11.