Chambers gunned down Milwaukee catcher Martin Maldonado at second base on Friday to end the top of the 11th inning during the Brewers' 5-4, 13-inning win.
The Pensacola, Fla., native calmly fielded the ball off the wall and quickly fired a one-hop throw to Pete Kozma at second.
"I knew I wouldn't be able to catch it, but I told myself that if I could get it quickly off the wall, I would have a chance," Chambers said.
Chambers, who came into the game in left field in the ninth inning, was recalled on Tuesday. This is his second stint on the Major League roster this season. He was also called up May 18 for 33 days.
Chambers made his first start May 22 against San Diego. He has appeared in 26 games this season and is hitting .256 with three RBIs. He joined the team last September and made five postseason appearances.
A 38th-round choice by St. Louis in the 2007 First-Year Player Draft, Chambers picked up the assist in his 44th big league game.
"As an outfielder, you always want to show off your arm," he said. "It felt good, real good."