Goals from Cedric Kipre, Karlan Grant and Grady Diangana saw the Baggies run out 3-0 winners at The Hawthorns.
But the score line didn’t quite tell the story of the game with the visitors sitting in a low block and showing next to no ambition right from the very first whistle.
Darren Ferguson's side came with a game plan to frustrate and time waste in the hope of pinching a point.
And they almost did it - with Kipre finally opening the scoring in the 78th minute.
Substitute Callum Robinson then grabbed two assists when he set-up Grant and fellow sub Diangana – with Diangana producing an exquisite finish for his strike.
“Until the first goal, it was the story of the season so far,” Ismael said.
“But as always with a good story, there was a happy ending. Hopefully we can now take the next step (against Preston North End) on Wednesday.
“The game was how we expected, the opponent came, didn’t want to play, wasted time and tried to take time from the clock - they didn’t shoot once on target. You have to stay calm, to stay patient.
“We might’ve scored earlier, with (Daryl) Dike three times.
“But I said to the guys (at half-time) we’re on the right way, we’re controlling the game - just make sure we come wide with the crosses and counter press to put them under pressure.
“We have to deal with these situations at the minute, to change the story, to force the ball over the line and then the goal set the energy free and it was much easier for the players.
We’ve got impact from the bench with Robbo and especially Diangana. It’s helped me and my staff to make better decisions when we have all the players together and we have the possibility to change the way of the game from the bench.
“We just need to keep going, continue to win games and the next one is very important for us because it gives us the possibility to win again.”
While Albion’s first goal was scrappy, they showed their quality with their second and third.
And Ismael said that’s because Peterborough had to come out and show some ambition.
“We showed our quality when the opponent was ready to play football,” the Frenchman said.
“Then it became a good game, we were able to run in behind and show the quality of our players.
“The first goal got the breakthrough and you could fee straight away the energy from the players, their heads were higher, their chests were wider.
“I think we showed spirit to get the three goals and control the game. We deserved to win but now it’s all about taking the next step and Wednesday.”
In the end the only disappointment for Albion was that Dike came off with a hamstring problem.
And Ismael said the striker will now miss the next two games against Preston North End and Millwall.
"We saw straight away the difference you have when the target man in the middle is able to challenge the centre backs dramatically," Ismael said on the American's performance.
"The quality of the crossing is getting better from our players.
"It’s a dream if he can score but we saw straight away the impact and unfortunately in the second half he picked up the injury.
We will see on Monday when he has a scan, but for sure the next two games he will miss because we cannot afford to take any risks now, especially after the Millwall game we have another 11 days.
!Now he can have 20 days to get ready for the Sheffield United game if the injury is not too bad."