PHOENIX -- Justin Upton is still young.

The 23-year-old right fielder does have five years of big league experience, but D-backs manager Kirk Gibson knows Upton has grown up because he's seen it.

"He's just more polished," Gibson said. "He understands his role much better and he's not trying to live up to what everybody else thinks he should be."

On Thursday, Upton hit a walk-off home run in the 10th inning to propel the D-backs to a much-needed 3-2 victory over the Giants.

Gibson said that earlier this season, in Houston, he talked with Upton to reaffirm that he didn't care if he was a superstar.

"I just want him to be a championship player," Gibson said.

Upton said the difference between the two is simple: winning.

"For me, everybody that's on a winning team is a championship player," he said. "They did something to contribute to that."

Upton entered Friday's contest against the White Sox hitting .291 with 12 home runs and 35 RBIs, but he understands he not a finished product.

"I wouldn't call myself a complete hitter yet," Upton said. "But I think it's about not worrying what I'm doing; It's worrying about what can I do to make the team better?"

He then went 3-for-3 with a walk, RBI and a run scored in Friday's 4-1 victory to raise his average to .299 and give him five straigth multihit games

Gibson gets in on walk-off celebration

PHOENIX -- It was three days in the making.

After D-backs right-fielder Justin Upton hit a walk-off home run in the 10th inning of Thursday night's game, joining the mob of teammates waiting for him at home plate was manager Kirk Gibson.

"I said, 'I don't even know what I'm doing out here,'" Gibson said. "We never really did that back in my day."

Gibson said that in the previous two nights, both of which held opportunities for the D-backs to walk off, he told himself he would rush the field if the time was right, even though managers rarely participate in walk-off celebrations.

"I was telling myself, 'If we win this, I'm going out there,'" Gibson said.

"And then it happened and I wasn't even thinking about it," he continued. "I was kind of thinking about the game and what guys were coming in and how I was going to proceed from there, and boom."

Upton said he didn't know Gibson was in there until he saw the highlight.

"That's cool," Upton said. "He's always just as excited as everybody else."

"It was a good time and a good celebration," Gibson said. "But here we are today."