The Super Bowl champ reportedly touched down in Sin City around 8:30 AM Saturday according to People and seemingly confirmed by online flight records -- marking the end of one of the fastest lovers' liaisons in recent memory.

We broke the story ... sources told us Travis took off from Sydney on Saturday afternoon but he landed Saturday morning -- Vegas local time, 'cause of the time change.

It's all pretty confusing but basically, TK was in Syndey for about two days, landing Wednesday before hopping right back on a jet and taking off for Vegas to hang out with his Chiefs teammates.

His reason for jetting back ... he wants to celebrate with his K.C. teammates in the aftermath of their third Super Bowl win in 5 years, and he's heading back to the site of their most recent conquest to live it up.

Kelce's guys have already started the party BTW ... with Patrick Mahomes and some of his teammates partying at Zouk Nightclub Friday night.

Kelce packed a ton of activities into his two days with Taylor ... with the pair hitting the zoo down in Sydney before Travis watched his lady live in concert -- where the two engaged in some passionate PDA.

T-Swift also showed her man some love during the show when she changed up the lyrics of "Karma" again to include a reference to him. Not the first time she's done it during her tour either ... talk about couple goals.

Bottom line, despite spending some time apart ... Traylor seems stronger than ever which falls in line with what we heard while researching our new documentary on their love story.