If you stay up, you're going to be half dead the next morning.
What I do is - if it's a really important match (like Team Liquid vs Sentinels), I sleep and wake up early, then rewatch shroud's twitch stream of the series before work hours (I love Shroud and he usually has Tarik, Asuna, Kyedae etc in his discord so it's really entertaining) and skip all the pauses and time between rounds. I go to sleep at 10-11 PM IST then wake up at 5-6 AM so it gives me plenty of time to watch. Also I don't open any social media so the results get spoiled. Not the best but at least my body feels okay and my mind works.
And for the unimportant matches (C9 vs VS) I just rewatch the last map or the first, depending on the score which I check on vlr before logging in.
Earlier during CSGO days I used to stay up nights but those were college days and I could afford it. Now it's just not worth it. I'd rather invest the time in proper sleep.