Manager Darren Ferguson praised former non-league striker Kyle Vassell after his his fourth goal in as many matches earned Peterborough victory at Bradford.
Vassell scored the only goal of the game in the 57th minute to end the Bantams' unbeaten start to the campaign. Substitute Michael Smith collected a long diagonal ball from Shaun Brisley and supplied a pass to the unmarked Vassell, who scored with a right-foot shot into the far top corner of the net.
Ferguson said: "He is a lovely lad, always smiling, wants to learn and is always asking questions. He has done a lot better than I thought - four goals in four games is outstanding."
Vassell joined Peterborough from Bishop's Stortford last November for an undisclosed fee.
Ferguson continued: "We had the better chances and the goal Kyle scored deserved to win the game. It was a fantastic finish.
"Whenever you come to Bradford you have to deal with balls in the box a lot and we did that. I don't think they had many clear cut chances. It was a really good team performance.
"I was pleased with the players. Every game we play they get better."
Peterborough's goal came two minutes after Bradford's influential central defender Andrew Davies was led off the field with an arm injury following a collision with his own keeper as Jordan Pickford came off his line to punch clear. The lengthy on the field treatment contributed to nine minutes of stoppage time.
Bantams boss Phil Parkinson said Davies had gone to hospital for an x-ray to assess the extent of the injury.
"He has had a great start to the season and he is probably fitter than he has ever been," said Parkinson. "We have lost him for a while,but we have enough players to come in and do a job.
"Players get injured. We have to make sure we respond in the right way and the players who come in keep hold of the shirt."
Parkinson, who now has the task of plotting the downfall of Bradford's West Yorkshire neighbours Leeds in Wednesday's Capital One Cup second-round at Valley Parade, added: "I thought the first half was a good game of football. I was pleased with how we played, but our crossing was disappointing and too many balls went into the keeper's arms.
"The second half became scrappy because of the stoppages and Peterborough took the sting out of the game after the goal. We lost our way, but got it together again when Billy Knott went into the centre of midfield. However, we couldn't find that moment of quality to put us back in the game.
"Now we prepare for Leeds United and we want to pick a team that will produce a performance that will make the club and the city of Bradford proud. That is our aim."