Mark McGwire answered Sammy Sosa's 66th homer with his 66th Friday night, a two-run shot in the fifth inning against Montreal reliever Shayne Bennett.
When Sosa took the lead in the home run derby for only the second time all season in the fourth inning, it prompted a collective groan from a sellout crowd at Busch Stadium and booing when Sosa's home run number was changed on the scoreboard.
With a runner on first, two outs and the fans on their feet, McGwire hit a 1-2 pitch an estimated at 375 feet into the left-field stands. It was his second homer this year against Montreal and first since he connected off Trey Moore on April 21.
On the first pitch from Bennett, McGwire nearly homered on a ball that landed just to the left of the foul pole in the upper deck in left field. Busch Stadium personnel inadvertently set off fireworks after the near-miss, but the fans didn't have to wait long for the real thing.
Sosa led the home run race for about an hour on Aug. 19 before McGwire regained the lead with his 48th and 49th homers later in the same game at Chicago. Sosa tied McGwire at 65 with two home runs Wednesday at Milwaukee, snapping his 0-for-21 slump.
McGwire had been 2-for-11 on the homestand with a pair of singles before homering Friday night. He extended his NL record to 161 walks on a full count in the first against Miguel Batista and lined out to left in the third.
McGwire and Sosa each have two games left after Friday night, with McGwire's at home against the Expos and Sosa's on the road against the Astros.
The latest homer was No. 453 of McGwire's career, putting him in 20th place ahead of Carl Yastrzemski. He has hit 176 homers the last three seasons.
In 204 career games with the Cardinals, McGwire has 90 homers, 182 RBIs
and 204 walks. He has 47 homers and 95 RBIs in 104 career games at Busch