Dirk Nowitzki Ridin' Lazy River ... In a Baseball Stadium!!!

Dirk Nowitzki is an aquatic pioneer -- 'cause the NBA star just became the FIRST person to float in a lazy river INSIDE A BASEBALL STADIUM!!

The Frisco RoughRiders minor league baseball team invited Dirk to break in their brand new $1.5 MILLION river -- located in the outfield of Dr. Pepper Ballpark in Frisco, TX.

The river officially opens Friday.

#DontPeeInThePool