PHOENIX — Before last night’s game against Arizona, struggling Boston right fielder J.D. Drew was hoping for a little more luck at the plate.

After sitting out two games in Oakland, he hit the ball hard in three of his four at-bats on Thursday, yet wound up just 1-for-4.

“When I square up a ball, it seems like I hit it hard at somebody. I need some of those to hit the grass,” he said.

Well, last night, the balls Drew hit didn’t find nice soft landing spots in the grass at Chase Field. They found better destinations.

Drew clouted two drives that crash-landed in the seats, a pair of three-run homers that sparked the Red Sox to a 10-3 victory over the Diamondbacks before a crowd of 40,435.

The first one traveled just to the left of the 413-foot marker in center field and gave the Red Sox a 4-0 lead at the expense of walk-prone left-hander Doug Davis.

Considering the depths of his slump – it was only his second extra-base hit in 54 at-bats and his first HR in 114 at-bats — that might have been a nice enough night for Drew, who was batting .224 with two homers and 17 RBI and not exactly earning the $70-million, 5-year deal the Sox had lavished on him as a free agent.

But there was more. In the sixth, with two on and one out, Drew pulled a three-run homer to right off right-hander Edgar Gonzalez, giving the Red Sox a commanding 9-1 lead. And just for good measure, Drew laced a double to right-center in the eighth, delivering Eric Hinske from first base for a 10-1 advantage.

It was the 12th two-homer game of Drew’s career, the last of which had come for the Dodgers last Aug. 25, 2006, also against the Diamondbacks.

The seven RBI, though, constituted a career high for Drew. Twice he had driven in five runs in a game, on April 6, 2000 for St. Louis against the Cubs and on June 30, 2004, for Atlanta against Florida.

Drew’s sudden and unexpected power show – he doubled his home-run output for the season — wasn’t the only highlight of the night for the Sox.

Julio Lugo, another megabucks free-agent signing not justifying his big contract (4 years, $36 million) led off the game with a homer to left.

It was his fourth homer of the year, but only his second extra-base hit in 67 at-bats.

On the mound, meanwhile, was unbeaten Josh Beckett, who cruised to 9-0, surrendering three runs, only two of which were earned, in eight innings.

Beckett, backed by Drew’s power show and contributions from Lugo and Manny Ramirez (RBI single), became the sixth pitcher in Red Sox history to win his first nine decisions in a season.

Roger Clemens was the last, going a Sox record 14-0 to begin the 1986 season.

But the star of the night, obviously, was J.D. Drew, who was playing against his younger brother, Stephen, the Diamondbacks’ shortstop.

And his success against Arizona probably should have been expected.

Last year, as a member of the Dodgers, Drew hit a sizzling .412 (28 for 68) with seven homers and 30 RBI in 18 games against the Diamondbacks.

From 2004 to 2006, Drew batted .383 (51 for 133) with 12 homers and 33 RBI in 35 games against Arizona.

The seeds of his outburst, though, may have been sown in Oakland when manager Terry Francona gave him two days off to clear his head and work with batting coach Dave Magadan.

Drew lined out to short, was robbed of a hit when a hot grounder was turned into a 1-6-3 out and smoked a single to center in his four trips to the plate Thursday.

“I’m not going to change anything,” said Drew before the game. “I’m going to take the same good swings, but the key is you want to see some results.”

He certainly did last night.

skrasner@projo.com