Hugill scored the opener as the Baggies secured a convincing 3-0 victory over Nigel Pearson’s side on Saturday.
But while Ismael was delighted to see the striker get off the mark, Hugill missed three other excellent opportunities in the game.
And the boss has now challenged the forward to become more ruthless in front of goal – with Ismael revealing the striker has been doing extra work with coach James Morrison in a bid to find his scoring touch.
“I think it was a great performance,” Ismael said when asked about Hugill’s display against Bristol City.
“I told him at half-time it’s your day today, you need to stay focused and you will get more chances.
“He had three situations one-v-one against the keeper when he needed to score.
“But his goal was his reward for the hard work he puts in.
“We have been working in training on ways for him to score, after training he stays late with James Morrison.
“Now he has got his reward but it needs to stay this way because he is a very important player for us.”
Albion put in a hugely impressive performance on Saturday with Ismael appearing to tweak his high intensity style of play.
With Robert Snodgrass shining in central midfield, the Baggies played with a bit more composure.
But the boss didn’t want to go into too much detail when asked what he had changed.
“I don’t want to give away all the secrets but it was about giving more freedom to the players and stretching the opponents more,” he said.
“We give players solutions of how we want to see things.
“We take our responsibility as a head coach and a staff and the players have to take responsibility for the quality and how he plays the ball and how is the quality of his passes.
“This is how we wanted to combine to have a better game from us and against Bristol City it was a good step in the right direction.
“Everything was not perfect but it was a good step in the right direction.”