Barry Bonds hit the 748th home run of his career in a 9-5 loss Sunday in Boston, moving the San Francisco Giants slugger within seven of tying Hank Aaron's all-time record.

Bonds connected on a 1-0 pitch from knuckleballer Tim Wakefield to lead off the sixth inning, lining a shot into the Giants bullpen. It was his 14th homer of the season, and first ever at Fenway Park.

Barry Bonds, right, smacks his 748th career homer off Red Sox pitcher Tim Wakefield as catcher Doug Mirabelli looks on Sunday at Fenway Park.
(Winslow Townson/Associated Press)

"I believe I had two, but we'll leave it at one," Bonds said, still smarting over a high fly ball that was ruled foul on Friday night, postponing his first Fenway homer for two more days.

But Sunday's blast merely cut San Francisco's deficit to 8-4, and Boston's Manny Ramirez padded his team's lead with a solo homer to help the Red Sox complete a sweep of the three-game interleague series.

Fans booed when Bonds stepped to the plate, cheered briefly when the ball went over right-fielder J.D. Drew's outstretched glove and then resumed booing as Bonds circled the bases.

Bonds, 42, had never played at hallowed Fenway — baseball's oldest stadium — before Friday night's series opener.

Fenway is the 36th different ballpark in which he's homered, and Wakefield is the 441st pitcher to surrender one of his homers.

The last time Bonds homered off a knuckleballer was when he hit No. 73 of his 2001 season off Los Angeles Dodger Dennis Springer, to establish the single-season record.

Bonds had been hitless in eight at-bats against Wakefield — a former teammate from his days with the Pittsburgh Pirates — even joking that the pitches were too slow to hit hard.

"I think my age got me slower so I'm more able to time it a bit better," Bonds said with a smile after going 2-for-3 on Sunday. "I tip my cap to him. He came after me in every at-bat. He gave me something to hit."

With files from the Associated Press