Hoskins fires in late winner as boss Patterson continues to earn results
The young striker, on loan from Southampton, had been on the field only three minutes and netted from a tight angle with seven minutes to go.
The win handed caretaker boss Darren Patterson his third win in four games as the search continues for a successor to Andy Scott.
Rotherham pinned the hosts back in the first half and should have ended it at least a couple of goals to the good. The recalled Dale Tonge had a close range drive well saved and Ben Pringle hit an effort just over from close range.
Gareth Evans scuffed another decent chance wide before Pringle struck the first blow on 33 minutes. He took aim from 25 yards out and his low shot squirmed under Jack Turner.
It took Wimbledon nearly half an hour to produce their first serious effort, an angled curler from George Moncur, and they could count themselves lucky to go in at half-time only one down.
They came out in more determined mood for the second half and forced Rhys Taylor into his first serious save, blocking a header from Chris Bush with his legs. Wimbledon equalised on 66 minutes when Luke Moore fired a sweet effort in off a post.
The same player popped up with a vital clearance off the line from the lively Lewis Grabban to keep the scores level before Hoskins stole the show with his first goal in league football.
Wimbledon: Turner; Hatton, Gwillim, Mitchel-King, Johnson (Bush, 46), Wellard, Moncur, Yussuff (Knott, 84), Djilali (Jolley, 46), L Moore, Midson. Unused substitutes: Brown, Harrison, Knott.
Rotherham United: R Taylor; Tonge, Wood, Cresswell, Mullins, Grabban, J Taylor, Schofield, Evans (Harrison, 75), Pringle (Hoskins, 80), Revell. Unused substitutes: Warrington, Newey, Cadogan.
Referee: Dave Phillips.
Man of the match: Lewis Grabban.