That ties Rodriguez -- who has the most home runs of any active player -- with Mays for fourth place on Major League Baseball's all-time career home run list.
But Mays is still ahead in glory, as A-Rod is still freshly marked by the scandal over performance enhancing drugs
that led to his suspension last season.
Thundering boos from Boston fans greeted Rodriguez as he came on as a pinch-hitter in the eighth inning of a tie game, and the boos grew louder when he belted a 94 mph 3-0 pitch from Junichi Tazawa over Fenway Park's Green Monster, giving the Yankees a 3-2 lead and the eventual victory over the Red Sox.
The victory keeps the Yankees in first place in the American League East, a game ahead of second-place Tampa Bay and two games ahead of the Red Sox in third.
During his home run trot, Rodriguez clapped and pumped his right fist, then his teammates cheered and slapped number 13 on the back, as he descended into the dugout. A smattering of people in the crowd applauded.
In interviews after the game, Rodriguez appeared humble.
"I don't know what it means," he told MLB.com
. "I'm actually very excited; just trying to stay in the moment. It's good to do it in a good team win. I got emotional there."
As he stood on the field in a solitary moment, tears broke loose.
Scandal or no, Bostonians probably would have booed Rodriguez, given that he plays for the Yankees.
But the jeers were deafening and echoed across social media at the target of disdain -- the drug scandal that dragged on for two years from the time the Miami New Times
published the allegation in January 2013, until the time Rodriguez wrote an apology this past February.
In between, he launched lawsuits against MLB and the Yankees' team doctor, and the team came under pressure to buck his then-record $275 million, 10-year contract. Rodriguez was due a $6 million marketing bonus for tying Mays' record, but The New York Times reported
that, with relations soured, the team may not pay.
The scandal got Rodriguez a 162-game suspension that nixed his 2014 season. And it was his second time around. Another performance enhancing drug scandal
snagged him in 2009.
"A-Rod's stats should be deleted from MLB history," scathed a Twitter user. "Willie would have hit 800 homers if he'd been on steroids like A-Rod," scorned another.
But plenty of people defended him. "A-Rod is one of the best hitters to ever play the game get off his back," a fan tweeted.
And many praised Friday's achievement, including the author of the 660 benchmark himself, Willie Mays.
"Congratulations to Alex Rodriguez on his 660th home run," Mays said in a statement. "Milestones in baseball are meant to be broken and I wish him continued success throughout his career."
Rodriquez has passed many career milestones.
In 1998, he became the third player to make it into the 40-40 club, hitting 40 home runs and stealing 40 bases in one season. He had 42 homers and 46 stolen bases.
In 2000, he signed the largest sports contract in history at the time, a 10-year, $252 million dollar deal with the Texas Rangers.
In 2007, he became the youngest player ever to hit 500 home runs, and in 2010 the youngest player to hit 600 home runs, and one of eight players ever to do it. He was on trajectory to reach a historic summit. But scandal and age caught up with him: He has hit just 47 homers since 2010, including six this season.
At 660 home runs, Rodriguez is more than 100 behind Barry Bonds, baseball's all-time leader at 762.