As things stand, Darren Ferguson's side are seven points clear in second place, with just four matches of the season left to go. However, Tuesday night's shock 1-0 loss to Gillingham was a real wake-up call for the Posh, who can't afford any complacency at such a crucial stage of the season.
Next up, Peterborough will look to bounce back this weekend, when they travel to take on fellow promotion-chasers Charlton Athletic - a side they beat 2-1 when they last met back in January - at The Valley.
Here's the latest rundown of the current League One promotion odds, after another action-packed night of third-tier football:
Here's the latest rundown of the current League One promotion odds, after another action-packed night of third-tier football:
5. Oxford United - current odds: 20/1
They've won three out of their last five games, and are only one point off the top six as things stand. The bookies don't fancy them, however, given that they've only got three matches of their season left to play. Photo: Richard Heathcote
6. Portsmouth - current odds: 6/1
Pompey have a real slog ahead of them to try and make the play-offs, and the bookies fancy them to play their fifth League One campaign in a row next season. They're next game against Bristol Rovers is a 'must win'. Photo: Bryn Lennon
7. Charlton Athletic - current odds: 5/1
The Addicks suffered a hammer-blow in losing Lee Bowyer to Birmingham City, who now look likely to avoid relegation down to League One. Charlton, in sixth, hold some precious games in hand over the sides directly below them. Photo: Harry Trump
8. Blackpool - current odds: 3/1
Goal machine Jerry Yates has given the Tangerines a fighting chance of promotion this season, and he could be the key to Blackpool going up via the play-offs - something they've done six times in the past across three competitions. Photo: Catherine Ivill