While The Underpin probably hijacked your delve run at some point during Season 8 while you were fighting against Elites this season, a player was so lucky that the boss spawned right as they were facing off against the final delve boss, something we’ve haven’t seen reported until now.
The player who goes by the the name Aruhi on Reddit, shared a screenshot with the final boss killed and the pile of gold that spawns when you kill The Underpin.
What’s even worse, for all their effort, the player only received a Champion trinket, as they’ve got a 
Delver’s Bounty at the end of the delve they did before this one.
