Eagles' Darius Slay Gifts INT Ball To James Harden, Signs It Afterward

Eagles star Darius Slay made sure James Harden left "Monday Night Football" a happy man -- because after intercepting Kirk Cousins, he gifted the 76ers point guard the INT football ... and then he signed it for him after the game!

Darius lived up to his "Big Play Slay" nickname on Monday night against the Minnesota Vikings -- picking off two passes --- and Harden had a front-row seat to witness the defensive masterpiece.

And, on Slay's first pick, the Vikings -- who had been trailing Philly 24-7 in the 3rd quarter -- were driving down the field ... but the DB stepped in front Justin Jefferson to nab Cousins' throw, and then he bolted over to James.

Slay handed him the ball and slapped his hand -- all while Harden had a big smile on his face.

After the game, Slay found Harden in the bowels of Lincoln Financial Field and autographed the pigskin for him.

"First Eagles game was lit!" Harden said of it all on Twitter afterward. "keep ballin bro @bigplay24slay."