The main event of WrestleMania 36 wasn't what you thought it was and it also aired on WWE Raw.
If it sounds confusing, it kind of what.
On WWE Raw, footage was shown of McIntyre returning to the ring following his WWE Title victory against Brock Lesnar for an interview. Technically, it was still WrestleMania. The Big Show interrupted McIntyre's promo and baited McIntyre into giving him a WWE Title match by slapping him.
So, it was official. Drew McIntyre vs. The Big Show with the WrestleMania backdrop present. Big Show gave McIntyre everything he could handle, but McIntyre needed just one Claymore kick to put Show away to retain his WWE Title.
There you have it. The true main event of WrestleMania 36, as shown on WWE Raw; Drew McIntyre vs. The Big Show.