The kings of the comeback last season, the Diamondbacks have been fast starters in 2012, scoring seven runs the first two innings their first two games.
Hill drove in three of those: A solo homer off Madison Bumgarner (0-1) in the first inning and a two-run shot in the second. Young also hit the first of his RBI doubles in the first, giving starter Daniel Hudson (1-0) just enough cushion to open with a victory after struggling early last season.
J.J. Putz worked a perfect ninth for his second straight save.
The Diamondbacks had a successful debut as NL West champions, beating Tim Lincecum and the Giants 5-4 Friday after a pregame ceremony to celebrate their title.
Staff ace Ian Kennedy had a solid start after winning 21 games last season, Young and Paul Goldschmidt homered off Lincecum in the first inning and Ryan Roberts had a tiebreaking two-run double in the sixth inning in front of the fourth-largest crowd in Chase Field history.
All the pomp and pageantry of Opening Day over, it was time to get on with the rest of the season.
And, just like the day before, the Diamondbacks got rolling right away.
Hill, second in the lineup after hitting eighth in the opener, got things started with a solo homer that curled around the foul pole left. Young added a run-scoring double high off the wall later in the inning, though Bumgarner escaped further damage by getting Jason Kubel to hit into an inning-ending double play.
Hill made it 4-0 in the second after working a long at-bat for a two-run homer just over the wall in left and his fourth career multihomer game.
Hudson pitched well after a rough start to the 2011 season, finishing 16-12 with a 3.49 ERA after opening 0-4. He was a steady presence in the rotation behind Kennedy, pitching into the sixth inning in eight of his final nine starts as the Diamondbacks surged toward the playoffs.
Hudson started off smoothly against the Giants, retiring the first eight batters he faced, until Sandoval hit a two-run homer to right in the fourth inning to cut Arizona's lead in half, to 4-2. Tiring in the seventh inning, Hudson gave up another two-run homer, this one to Pill, who came in as a pinch hitter.
Hudson was done after that, leaving with a one-run lead after allowing four runs on four hits in 6 2/3 innings.
Like Hudson, Bumgarner got the 2011 season off to a shaky start, losing his first six decisions and nine of 12. He, too, turned it around late, going 10-4 with a 2.62 ERA over his final 18 starts.
The big left-hander struggled early and didn't last long against Arizona, allowing four runs on seven hits before being lifted for a pinch hitter in the top of the fifth.
Young hit his second double off Dan Otero in the fifth inning to put Arizona up 5-2.
Baltimore Ravens offensive tackle Michael Oher threw out the ceremonial first pitch. It was a strike -- after bouncing about 15 short off the dirt. ... RHP Josh Collmenter will make his first start of 2012 Sunday against the Giants after matching Arizona's rookie record with 10 wins last season. ... RHP Matt Cain will start for the Giants on Sunday after going 12-11 with a 2.88 ERA in 33 starts last season. ... Arizona has won seven straight against San Francisco, its longest streak ever against the Giants.