With his second-inning leadoff shot to left field against Padres right-hander Clay Hensley on Saturday night at PETCO Park, Bonds tied Aaron's cherished Major League Baseball career-best home run mark, and after the next one, he will be all alone in first place on the all-time list.

The homer, his 21st of the season and first in six games (28 plate appearances), ended Aaron's more than 33-year reign as MLB's home run king and came with Commissioner Bud Selig in attendance as part of a sellout crowd.

"This has been a real tough situation. This is the hardest thing I've ever had to go through in my entire career," Bonds said long after the Giants dropped a 3-2 decision to the Padres in 12 innings. "It's a different feeling than any of the other [milestones]. I'm really lost for words at this moment. I think when I sit back and can grasp all of this I'll be able to say a little more a little later. But I'm still in a daze myself right now."

As a member of the Braves, Aaron passed Babe Ruth into first place with his 715th homer on April 8, 1974, at Atlanta-Fulton County Stadium, where the Braves began to play when they moved from Milwaukee after the 1965 season. It came in the fourth inning off Dodgers left-hander Al Downing.

Selig, the former owner of the Brewers, was a fan of the then-Milwaukee Braves in Aaron's early years. After the hard-fought-for 715th homer, coming at a time when overt racism plagued Aaron's chase of Ruth, Selig utilized Aaron as the Brewers' designated hitter for the last two years of his career.

Selig was stoic Saturday night as he attended his 10th game during the current chase and finally saw his first Bonds homer, declining to talk to reporters. Instead he released a statement congratulating Bonds for his feat.

"No matter what anybody thinks of the controversy surrounding this event, Mr. Bonds' achievement is noteworthy and remarkable," said Selig, who planned to be at the ballpark for Sunday's game.

Bonds said emphatically he will not play in the series finale, saying instead that he wanted to "celebrate with his family." Then it will be on to San Francisco on Monday night, where Bonds will have numerous cracks at the record during a seven-game homestand against the Nationals and the Pirates.

Selig doesn't expect to be in attendance for games there on Monday, Tuesday and Wednesday nights because he needs to be in New York and Milwaukee to tend to other baseball business. Hall of Famer Frank Robinson, an advisor for Major League Baseball, is slated to be there in his stead.

Bonds, who had started nine consecutive games, said he can begin to relax a little bit now.

"The hardest part is over," he said. "That was the hardest one."

It was Bonds' first off Hensley, who became the 445th pitcher to allow at least one homer to Bonds in his 22-year career. Given the suspicions that have surrounded Bonds, Hensley's role is worth noting, as he was suspended for 15 games in the Minor Leagues when he tested positive for a performance-enhancing substance in 2005.

It was Bonds' fourth homer at PETCO Park and 87th against the Padres, far and away his most against an opposing club.

For those who wondered what the scene would be like if Bonds hit one of his big ones on the road, as soon as it hit the electronic advertising board at the edge of the second deck in left field 382 feet away, the partisan Padres fans began a long ovation.

"I want to thank the San Diego fans. I thought that was outstanding," said Bonds, who was walked the other three times he came to the plate, mostly to derisive jeers aimed at the Padres pitchers. "It's been a fun ride. I mean, I really don't know what to say about the way San Diego handled it and the way their fans handled it."

Bonds, who had taken a half-hour of early batting practice long before the game Saturday, was joyous as he reached the plate, giving a huge bear hug to his teenage son, Nikolai, who has been there for almost all his recent milestone homers, albeit at earlier stages of growth.

Bonds was then mobbed by his teammates as he strode back to the Giants third-base-side dugout. And just to punctuate the amazing moment, the fans gave him another ovation as he went back out to left field after the half-inning, Bonds doffing his cap in appreciation.

The ball was retrieved in Section 130, Row 1, Seat 18 by a man identified during the game as Adam Hughes, 33, from La Jolla, Calif.

"I saw it hit above me," Hughes said. "It came down and was on the ground. I just happened to be in the right place at the right time. I think [Bonds reaching 755] is quite an accomplishment for one man."

Once Alex Rodriguez had hit his 500th homer earlier in the day at Yankee Stadium, Bonds became serious. He had said, half in jest on Friday night, that he was waiting for A-Rod to reach his milestone before Bonds at least tied Aaron, which he did on a 2-1 fastball up and out of the strike zone from Hensley.

"I obviously wasn't trying to leave the pitch up," Hensley said. "But he hit a fastball that was up. It was actually off the plate, really off the plate, but it was high and it was up, and he went with the pitch."

Hours earlier, with no fans and just a smattering of reporters in the ballpark, Bonds emerged from the clubhouse to take early BP with Giants manager Bruce Bochy doing most of the pitching. Bonds took 11 rounds and 113 swings, hitting 17 bolts all over the nearly four-year-old ballpark.

Bonds said he was just trying to get away from the fans, away from the media and back to basics.

His first thought as he was rounding the bases upon hitting the homer at 7:29 p.m. PT?

"I finally did something mechanically right," said Bonds, who just turned 43 on July 24.

Bonds' career has been speckled by seasons of greatness, as his seven National League MVP awards attest. He also holds the single-season record for most homers with 73 in 2001.

Aaron did it with consistency, never hitting more than 47 homers in a single season -- and he did that in 1971. But his overall numbers were outstanding. He's the only player in history to amass more than 700 homers, 3,000 base hits and 2,000 RBIs.

Aaron's 2,297 RBIs are also baseball's all-time best and his 3,771 hits are third behind Pete Rose (4,256) and Ty Cobb (4,189).

Aaron was also a .305 lifetime hitter for his 23-year career, which began in Milwaukee with the Braves in 1954 and ended there with the Brewers in 1976. He played his final two seasons as a designated hitter in the American League and his last homer was hit at Milwaukee County Stadium on July 20 of that year.

Aaron was a 25-time All-Star, including the two games that were played each summer from 1959 to 1962, won two National League batting titles and led the league in homers and RBIs four times.

He was the NL MVP only once (in 1957, the year his Braves defeated the Yankees in the World Series for Milwaukee's only baseball championship) as compared to seven for Bonds, who needs 88 hits to reach 3,000 and 20 RBIs to hit the 2,000 mark.

Aaron was inducted in the Hall of Fame along with Robinson in 1982.

Though Aaron wasn't in attendance Saturday night and won't be in the days ahead as Bonds surpasses his record, the greatest left-handed home run hitter in Major League history had nothing except praise for him.

"We as baseball players, especially African-American baseball players, have so much respect for Hank Aaron," Bonds said. "He helped pave the road for what we're doing now. No one at any time, shape or form will ever get me to say anything different about Hank Aaron and what a great person he is and what a great athlete he is and how we as players all admire him."