Tim Cahill scored the winning goal as Everton advanced into the third round of the Carling Cup with a 2-1 victory over Peterborough at London Road.
The Barclays Premiership side had been comfortable leaders at the interval thanks to an own goal from Peterborough defender Jude Stirling.
The unfortunate Posh player deflected James Beattie's far post header past flat-footed keeper Mark Tyler in the 22nd minute.
But they were made to fight all the way after Trevor Benjamin levelled the scores in the 56th minute.
The first half own goal had put the Merseysiders in total control and, while they restricted their lowly opponents to few chances of note, they should have added to their tally by the interval.
Lee Carsley seemed set to increase their advantage but his vicious right-foot volley was turned around the post by the athletic Tyler as it made its way towards the top corner.
Peterborough, branded a laughing stock after the Sky TV series 'Big Ron Manager' charted their failure to reach the Coca-Cola League Two play-offs last season, were determined to prove those days had vanished for good when Justin Richards forced Joleon Lescott to clear a header off the line in the 15th minute.
Peterborough, now under the managerial tenure of former Lincoln boss Keith Alexander, also had a penalty appeal rejected by referee Ian Williamson in the 25th minute.
Posh midfielder Liam Davis managed to get clear of the Everton defence but found his path blocked by Blues defender Mark Hughes.
The League Two striker went down under Hughes' challenge but referee Williamson waved away their penalty appeals to the anger of the home fans.
But Alexander had clearly read the riot act to his side during the interval as Peterborough levelled the scored 11 minutes after the re-start.
Former Leicester striker Benjamin rose high above the Everton defence to direct Dean Holden's corner towards the top corner and although his effort was hooked clear in spectacular fashion by former Posh midfielder Simon Davies, it was adjudged to have crossed the line.
Two minutes later Benjamin headed wide from Adam Newton's cross as Everton began to look decidedly uncomfortable in defence for the first time in the game.
The anxiety was enough for Everton manager David Moyes to make a double substitution in the 63rd minute - replacing Andy Van Der Meyde Gary Naysmith with Cahill and Mikel Arteta.
The changes almost brought instant rewards with Davies, who began his career at London Road, forcing Tyler into a diving save with an angled drive.
But substitute Cahill spared Everton's blushes and broke Posh's hearts into the bargain with the winning goal just three minutes from time.
Peterborough failed to deal with the threat from Victor Anichebe and after the powerful striker forced Tyler into a fine save, the ball fell loose to Cahill who forced it home for his third goal of the season.
