Ladbrokes reported up to 10 in-play bets a second for a goal while those who backed him to score first benefitted from double odds of 8/1.
Arsenal are also subsequently trimmed to 7/1 for the FA Cup as a result of their progression to the next round.
Alex Donohue of Ladbrokes said: “Henry used to clobber us week in week out in his heydey. Tonight proved no different as his goal hit us for six both pre-match and in-play.”
FA Cup winner
Manchester Utd 9/2
Aston Villa 40/1
West Brom 50/1