Hoilett was introduced as a 60th-minute substitute for only his second Premier League appearance and injected life into a side which looked short on ideas.
He had the best chance of the game 13 minutes from full-time when he ran onto David Dunn's incisive through-ball to set up a one-on-one with goalkeeper Robert Green.
Hoilett attempted an ambitious 20-yard chip instead of going for a more straightforward option and the ball dropped onto the top of the net.
Nevertheless, he showed in half an hour that he has the potential to become a Premier League regular.
"We have an exciting young lad in Junior," said Allardyce of the player Blackburn have had on their books since he was 13 and who was loaned out to German clubs Paderborn and FC Pauli in the last couple of seasons.
"He played at Gillingham (and scored in Tuesday's 3-1 Carling Cup victory) and there is a bright future for him coming I think.
"But we don't want him to get too big-headed just yet and start getting carried away thinking he is this, that and the other.
"He is a sensible lad I hope. We'll introduce him slowly and develop him slowly.
"I think he showed enough yesterday to prove sometimes he can produce a little bit of brilliance.
"In that respect he is a little like Dunny (David Dunn), offering something that other players cannot which can open the door for you."
The two other significant factors from yesterday were Rovers' first clean sheet of the season, which brought their first point of the campaign.
Allardyce's teams have a reputation for being difficult to beat and despite finding the right formula last season to save them from relegation, injuries to key players have meant Rovers do not yet have that stability.
However, the manager was encouraged by the display against the Hammers.
"The defensive side was extremely good, never giving West Ham a sniff and I don't think Paul Robinson had a save to make all game," he added.
"That clean sheet is very important."