WASHINGTON -- It was hardly ideal timing for a 400th home run. For Albert Pujols, it happened in the fourth inning of a 13-inning loss to a last-place team -- and in a game in which he twisted his ankle trying to climb a rolled-up tarp.

The St. Louis Cardinals slugger led off the fourth against the Washington Nationals on Thursday night by sending an 0-1 fastball from starter Jordan Zimmermann into the right-center seats, becoming the 47th major leaguer to reach the milestone.

At 30 years, 222 days, Pujols became the third-youngest player to hit 400 homers. Alex Rodriguez hit No. 400 at 29 years, 316 days, and Ken Griffey Jr. reached the benchmark at 30 years, 141 days.

As soon as he completed his swing, Pujols stood and admired the shot. He was mobbed by teammates when he returned to the dugout after cutting the Nationals' lead to 3-2. He had been tied with Al Kaline and Andres Galarraga for 47th place on baseball's career list.