The Black Cats boss saw the Scotland international turn in a fine individual display last Sunday to pave the way for a 3-0 derby victory over Newcastle, in which he scored the final goal to cement an opening win of the Barclays Premier League campaign at the 10th attempt.
Fletcher, 28, is out of contract at the end of the season and, having been linked with a move away from the Stadium of Light in recent months, has found himself at the centre of uncertainty for some time.
However, Allardyce wants to see more of the same from the £12million man to the benefit of both him and the club.
The 61-year-old said: "Steve's like every centre-forward in the end
His hold-up play is very important to you because you can build off that - that in itself allows you to keep hold of possession a lot better - but ultimately in the end, you are judged on the number of goals you score.
"The more and more goals he scores, the more people will say Steven Fletcher is back to his best.
"In his position, it is one of the biggest challenges of his career because he is out of contract
When a player is out of contract and the club is in this position, I just want to see a player like Steven go out to help us to get where we want to get.
"Then everyone gets what they want - a new contract, we are okay in the Premier League and and we try to move forward from there
It should be his target."
Sunderland will attempt to build upon their derby success when they head for Goodison Park to face Everton on Sunday, although Allardyce will be looking for a significantly better performance after seeing his team play second fiddle to the Magpies on their own pitch before the penalty decision which saw Fabricio Coloccini controversially dismissed.
He said: "There's a lot more to come
I will be demanding a lot more
We are on the way to sorting one critical area which will help us survive this season, which is to stop not conceding silly goals."
Meanwhile, Allardyce was comfortable with the decision to uphold Coloccini's appeal against his red card, although remained convinced his challenge on Fletcher remained worthy of a penalty.
Asked if he was surprised, he said: "No
As long as everybody agrees it was a penalty - and there isn't one scrap of doubt in my mind that it was a penalty, as far as that was concerned.
"But in terms of the red card, that one that if it's been rescinded, it's fine by me."
Source : PA
Source: PA