Complex sentence: Gastelum was quickly rescheduled and faced Tim Kennedy in a middleweight bout on December 10,2016 at UFC 206, where he defeated him by TKO (via punches) at 2:45 of the 3rd round.
Split into simpler sentences: Gastelum was quickly rescheduled and faced Tim Kennedy in a middleweight bout on December 10,2016 at UFC 206. He defeated Kennedy by TKO (punches) at 2:45 of the 3rd round.