Is it "normal" that a rather low-accuracy user suddenly jumps to 99.6% and makes a perfect game?

My 3 last games: I won the 2 first games, and my opponent was playing at my level, just very regular 1500 blitz games.

I could feel the "rage" (the 2nd game he lost on time after some recovery), and he requested a rematch promptly.

Ok, go for it. Then, I see a completely different game, like when I'm playing against the comp on chess.com. And, indeed, his accuracy is rated 99.6%. He quickly left the "chat room" after.

I didn't want to block him, because I like playing higher rated people and learn, but, at least, when they belong to the mankind!
Should I block?

If you feel suspicious,you can report them

Its online chess...you will lose to many engine users over the years. So what...its an online rating. Doesnt mean squat. There is also the possibility that he just had a good game/games. Maybe you just had bad games. Forget about losing online games and rating points. Just have fun :)

Yes it is normal for a bad player to sometimes play 99.6% accuracy.  Sometimes I can on my best days.

Looked at your history and that guy clearly cheated. From your third game on, he didn't drop below 98% accuracy in any of his games for a while. Report him.

Ok, did it.
To avoid some confusion this is the user in question.
(who may not be cheating, that's chess.com call)

I have had 96-98 accuracies occasionally pop up ever since I started playing. I just get 90s much more frequently now.

If you feel like your opponent is cheating, then you should report them.

Yes he can lol, did he ever say he plays that good very often? Nooo... 

Large rating makes for a large head. I went through an egotistical phase as well.

This guy was pretty obviously cheating though so...

I forgot to tag blitz2009 in the first part, I was talking to him lol (obviously I didn’t make the clear)

Oops, now I see.

As a players of chess we already know that there are many ways for an event.
Maybve you was playing with two persons, logged with  the same account, sharing the same computer.

Lets suppose:
I log with my nickname and keep loged. And if a grand master is here by my side
playing together with me? And he help me to play?
The game should be different.

Remember that it  is just a hypothesis. 

But the first think I have for this statment is that your oponent is cheating.
However I can't prove, so  I can't accuse.