King Thanos vs Rune King Thor

-Random encounter
-No knowledge/Prep
-Win via KO/Death (NO BFR)
-Fight on an indestructible planet

Who wins?

Rune King Thor

King Thanos, he one shotted Galactus (killed him) and slaughtered the cosmic hierarchy, what chance does RKT have?

If we're to believe King Thanos defeated LT, Watcher and several other abstracts, he wins hands down. RKT could not replicate that level of power.