Taylor Swift‘s ready to watch her man take care of business against the Denver Broncos … pulling up to his Sunday afternoon game in K.C. in a biz-casual ensemble.

The singer-songwriter rolled into Arrowhead Stadium in a red and black checkered blazer, pulled over a low-cut black top … with a tiny skirt matching her jacket.

Clearly, she’s in her “No-Nonsense Era” … preparing to watch her boyfriend Travis Kelce‘s team beat up on their division rival.

Of course, there’s still a full game to be played … but, the Chiefs have looked really strong recently — including in last week’s overtime win against the Tampa Bay Buccaneers.

T-Swift looked jovial at that matchup … waving to fans and cheering her man on as he racked up his biggest game of the year — pulling in a career-high 14 catches for 100 yards.

She’s had a jam-packed weekend — not exactly out of the ordinary when she’s not touring — going out to dinner Friday night with her famous friend Zoë Kravitz.

Sunday’s for the beau however … and this may be the last game she attends for a while, ’cause she goes back on tour this Thursday in Toronto.