A dominant first-half display by Wigan failed to conjure a deadlock breaker and Posh's substitute Leon McKenzie's opener fired the hosts in front midway through the second half.
But Latics battled back and netted an equaliser eight minutes from time, courtesy of a freak own goal from Peterborough defender Mark Arber.
Wigan boss Paul Jewell was disappointed with his team's performance and admitted that they had been fortunate with their goal.
He said: "I thought for 20 minutes of the first half we played well. After that it was a scrappy game and I was disappointed with the way we played.
"I don't know why we should be sloppy. We should be full of confidence.
"We had some good chances and should have been a couple of goals up.
"We had lots of corners and the ball was flashing across the box but we didn't have anybody to stick it in the back of the net. Yet the ball drops to McKenzie in the box and he tucks it away."
But the Latics boss was pleased to see his team fight back to bag a point from the game, stretching their lead at the top of the table.
He said: "They were difficult conditions, the pitch was bobbly and it was windy. In the end, we were glad to get a point.
"Anything you get away from home is a bonus. But we are disappointed because we didn't play well."
The draw moved Latics on to 81 points from 36 games but with just 10 matches remaining, Jewell's feet are still firmly nailed to the ground.
He said: "We have worked extremely hard this year and we will have to continue to do that. Everyone is telling us that we are promoted but we are not.
"We know there is a long way to go – there are 30 points to play for. If you take your eye off the ball, you'll get done.
"When we go into work we don't speak about promotion. We just speak about trying to win the next game and trying to be better.
"If it happens, we will take it but we have achieved nothing yet."
The London Road clash saw former Peterborough hero Jimmy Bullard reunited with his old team-mates and the £275,000 steal was unlucky not to feature on the scoresheet.
Bullard said: "At one point, I thought one of my shots was going in but it went a couple of feet wide.
"I have enjoyed coming back here although I didn't really enjoy the game as I couldn't find any space! I had Helgi (Danielsson), Shieldsy (Tony Shields) and Gilly (Matthew Gill) on my back!"
Bullard's return also sparked Peterborough's charismatic boss Barry Fry to vent his frustration at being forced to sell his starman at a bargain price and he had a special message for Wigan chairman Dave Whelan.
Fry said: "Wigan got Jimmy Bullard for peanuts. I spoke to their chairman before the game and I told him to his face that if I had been in charge of the transfer, there is no way they would have got him.
"He laughed and said that he had been magnificent for them. He said that Jimmy was even better than they had thought and that he might come back for one of my players!"
Fry also paid tribute to Jewell's side but said that Arber's looping own goal over goalkeeper Mark Tyler was a cruel blow to his struggling side.
He said: "It was an absolutely wicked deflection and I thought Mark Tyler did not deserve to get beaten.
"But Wigan are a very talented, strong and capable side."
Article from the Wigan Evening Post.