Justin Herbert‘s a top-tier NFL quarterback, but he actually showed off his defensive skills Friday night — fending off a basketball headed right for his GF Madison Beers at the Lakers game!

The Chargers QB and his pop star girlfriend watched the Lakers take on the Minnesota Timberwolves from a pair of courtside seats at Crypto.com Arena … when a ball came off the court straight at them.

While Madison cowered away from the ball, her man leaped into action … throwing out a hand like a defensive back breaking up a pass to a wide receiver and swatting the ball away.

While Beer clearly isn’t going to the WNBA anytime soon, she did look great in a revealing black tank top while she sat next to her man … fresh off his team’s Thursday night drubbing of the Minnesota Vikings.

Herbert and Beer are one of the hottest new celebrity couples — confirming their relationship back in August — though they were far from the only bold-faced names in attendance at Friday night’s Western Conference matchup.

Dwight Howard, David Geffen, Jimmy Iovine and Corey Gamble all watched the game … as did LeBron James, who is still sidelined with an injury and hasn’t played in either of the Lakers’ first two contests this season.