The funny exchange happened late in the fourth quarter of Minnesota's win over L.A. ... when Russ thought he lined up a corner three, but instead, came up with nothing but air.

Broadcast cameras caught Towns -- who was in perfect position to grab the "rebound" -- immediately making fun of the dude over the shot, looking to the sky as if to see what caused Russ to miss everything.

The Timberwolves broadcasters got a kick out of Karl's reaction ... with one saying, "KAT is looking where the wind is," before asking, "Did somebody open up a door?"

Wolves star Patrick Beverly then got in on the ribbing ... clowning the Lakers during Minnesota's blowout win.

Pat Bev appeared to mouth "trash" -- while making a gesture with his nose as if something stunk -- after intercepting a pass from Westbrook and starting a T-Wolves fast break.

A short time later, Pat was seen staring down LeBron James and flexing in his direction ... before going over to give the King a pat on the backside.

The Minnesota fans in the arena ate it up ... and Pat played to the crowd -- but Russ appeared to be furious over it all afterward.

When being interviewed by reporters after the loss, Russ said he won't pay any attention to Minnesota's trash talk because "Nobody over there's done anything in the league."

Beverly eventually responded on Twitter, saying, "Playoffs every year. 2 western conference finals with 2 different Teams individual stats or team stats? I thought it was a team sport??"