Club Championship OTB v 1850 opponent

I re-joined my old local chess club after a 10 year hiatus due to moving out of town and more recently it being shut down due to covid.  It's been about a month playing weekly and we just started our Club Championship a week ago.  I played ok in my first tournament back and had a forfeit due to no show in my first round last week.  This week I was paired with one of our top players in our club and somebody I had never played in the past but knew of from being in the club.  He's an "ole timer" and been playing for a long time his current rating is 1861 and has been as high as 1962 in classical but he holds a 2023 in blitz.  Anyways the game was 60min + 15sec and I had the White pieces.  I outplayed him for the first 30 moves and miscalculated a move to where he later responded he was going to resign after that had I played it.  I ended up losing my advantage and was losing and then he miscalculated and ended up blundering the game back to me.