Richie Wellens had "no complaints" over the sending off of Ethan Galbraith even if ultimately led to a defeat at Wigan Athletic.
Jason Kerr got the only goal of the game on 73 minutes to hand the Latics a 1-0 win, the substitute scoring mere seconds after coming on.
But the game had swung on the Orient man's two yellows, the second seeing him walk three minutes before the interval.
"I can’t really remember the first [booking] but I’ve got no complaints about the second one, his foot was high and it was a fair booking," said Wellens.
"Until the sending off we dominated the game.
"It was too easy for us, the only threat they had was when we lost the ball in the middle of the pitch and they countered on us.
"I’m very proud of the team – to come to this stadium against a club that win the league whenever they are in League One.
"Wigan should be right at the top end of this division so to come here with really young players and play the way we did was excellent.
"It was comfortable for us at the back, I didn’t think they caused us any problems until they made a good substitution, taking [Charlie] Goode off and bringing on someone who was better on the ball at the back, which caused us problems.
"But we’ve been done by a set-play and we’ve got to be better with that.
“After that, they managed the game well, the referee allowed them to slow the game down, waste time, which you expect the opposition to do in that position."
Kerr's goal was from a short corner with the cross being delivered by Jonny Smith, who had arrived in the same substitution seconds before.
Orient had their chances before Galbraith's infractions, Darren Pratley firing one wide after being presented with an opportunity from a weak Luke Chambers header.
After the red card, it was attack versus defence, with Callum McManaman shooting just wide of the target at the beginning of the second period before substitute Charlie Kelman somehow headed wide from eight yards against his old club.
Wigan boss Shaun Maloney said the success was hugely important though.
He said: "The game obviously completely changed on the red card.
"Leyton Orient were good at times in the first half, we were okay. At times we were really creative, at other times we weren’t at our fluent best.
"The only positive from that was when Leyton Orient had possession I never felt like they were creating big opportunities to score.
"The second half was all about trying to stay patient, understand how we were going to break them down.
"They went straight to a five and a four and it isn’t easy trying to break down 10 men.
"It was hard for the players and every substitution we made was to become even more attacking.
"But I thought the players were really good because it certainly wasn’t easy for them.
"As you can see the winner came from a short corner and sometimes you need set-plays like that to get over the line."
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