Apart from a short period in the second half when substitute David Mooney had briefly equalised for Orient, City were largely in control for the vast majority of the Sky Bet League 1 contest, creating far more chances than their London visitors.
After a number of near-misses, a close range finish from Billy Knott three minutes from the break had deservedly given the Bantams a half time lead.
Mooney's leveller in the 75th minute threatened to dampen City's day but Orient strike partner Chris Dagnall's red card shortly afterwards gave the initiative almost instantly back to Phil Parkinson's men.
City didn't waste anytime getting back in front after Dagnall's dismissal, goals from hard-working duo Billy Clarke and Jon Stead within six minutes of the red card saw the Bantams back in the driving seat and on their way to three welcome points.
Coming only a week after the blow of Gillingham's painful last grasp equaliser, Parkin felt that, along with the Bantams' overall team performance, City's impressive quick-fire response to Mooney's goal was worthy of praise.
Parkin "Against a team tipped by many to do well this year, I felt we played really well and created a lot of chances.
"There was a great work ethic about us today (Saturday) and we looked like creating scoring opportunities when we got the ball moving forwards.
"We were a bit unfortunate with their goal - both centre halves have slipped and it was a superb finish from their striker - but I always felt we would create more chances today.
"Even before the (Chris Dagnall) sending off, we looked threatening the way we were playing going forward.
"Last week against Gillingham we ran out of time to respond when they scored but this week there was always enough time to react and we always felt positive we would win.
"It is credit to the lads that we came back though. They could have had the feeling of 'here we go again' when Orient equalised, but it was a very forceful response from the players.
"Certainly in the last twenty minutes of the first half, we were creating chance after chance really and we could have deservedly gone in at half time more than one goal up.
"For the players then to not get too frustrated following Orient's equaliser is full testament to them."
The goals from Knott, Clarke and Stead against Orient were no more than the trio deserved after the three of them had played their part in some fine attacking play from the Bantams throughout the afternoon.
Parkin added: "At the end of the day, a striker likes to work hard and work for the team but they also like to see their name in the paper on a Sunday morning having scored on the Saturday.
"It is always great for the team when both your strikers score, and that is obviously what has happened for us today. I'm pleased for Billy Clarke and Jon Stead to get their goals because their performances really merited them getting some reward.
"I'm delighted for Billy Knott as well. The gaffer has had faith in him by putting him back in the side in the middle of the pitch with Lids (Gary Liddle) and he has rewarded us with a goal.
"Billy is a player we know can get goals from midfield. If we keep chipping away at him and keep working with him on the training pitch, I'm sure that will happen."