580 rated player beat 890 rated player

he played very well in the opening but got cooked in the middlegame

This was my best game ever. Here is the link https://www.chess.com/analysis/game/live/142008040749?tab=review
Btw they also said my rating for that game was 1450
When I was 680-ish, I defeated 1700 rated players on multiple occasions
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This was my best game ever. Here is the link https://www.chess.com/analysis/game/live/142008040749?tab=review
Btw they also said my rating for that game was 1450