The two famous WAGs returned to their usual suite seats for K.C.'s Divisional Round matchup against the Buffalo Bills at Highmark Stadium ... and this time around, they had new company from Travis Kelce's All-Pro brother, Jason, his wife, Kylie, and Swift's gal pal, Cara Delevingne.

Naturally, the A-list box had plenty of booze for the occasion ... and Swift and Mahomes took advantage of that by giving each other a "cheers" before sipping some adult bevvies.

Mahomes documented the experience on her Instagram ... showing the whole group in great spirits as the Chiefs came away with the 27-24 victory -- and Swift was right in the middle of the pack for the shot.

Of course, Swift had a front-row seat for Jason's shirtless antics ... and cameras showed her absolutely stunned as he hopped out of the suite to make his way to the normies' section of the stadium.

The broadcast also cut to Taylor and Brittany after Kelce scored a key touchdown ... with the two hugging it out in celebration -- which was met with mixed reviews (after all, haters gonna hate, hate, hate).

Swift might be considered a good-luck charm at this point ... and TK clearly has her on his mind on the field, with many thinking he threw up some heart hands in her direction after one of his TDs.

The Chiefs will now travel to Baltimore to face off against the Ravens on Sunday ... and judging by Swift's warm welcome with Chiefs Kingdom over the course of the season, there's no way she's gonna miss that one, either.