(Reuters) - The familiar sight of Arizona beating San Francisco continued in spectacular fashion on Sunday as the Diamondbacks overcame a six-run deficit to once again spurn the Giants with a 7-6 victory.

The defending National League West champion D-Backs began the new season a lot like the last one, completing a three-game home sweep over their divisional rivals to capture their eighth straight win against the Giants dating back to 2011.

"Any time you sweep a team it's special and awesome, but especially against the Giants to continue on the win streak that we finished on last year," Arizona reliever Bryan Shaw told reporters after he closed things out in the ninth to record his first professional save.

San Francisco started brightly with three runs in the second and third innings - highlighted by Buster Posey's two-run home run in the third to put them ahead 6-0 - but Arizona quickly chipped away at the lead.

Lyle Overbay hit a two-run double in the fourth before he and Ryan Roberts smacked back-to-back home runs in the sixth to pull the home side within one.

The Diamondbacks scratched two more runs across in the seventh, including the winner when San Francisco catcher Posey failed to touch the plate on what would have been an out.

Giants manager Bruce Bochy was thrown out of the game for arguing the call and Arizona relied on their pitching to finish off the victory.

Reliever Wade Miley spelled starter Josh Collmenter, who had allowed all six runs in the first three innings, by tossing four scoreless innings to get the win and paving the way for Shaw.

Giants starter Matt Cain took the mound less than a week after signing a lucrative new six-year contract and was hoping to get San Francisco their first win but stumbled in the middle innings and allowed five runs in six innings.

"The thing about these guys is, almost any of them can take you deep," Cain said. "You have to concentrate on making good pitches to all of them. That's tough sometimes."

(Writing by Jahmal Corner in Los Angeles; editing by Nick Mulvenney)