But it took a shocking error by home 'keeper Dale Brightly to send Posh through.

He spilled George Boyd's harmless shot straight to Mackail-Smith who had an easy task to slot home.

The Posh striker was the FA Cup's leading goalscorer last term, but started this match on the substitutes' bench as manager Darren Ferguson gave starts to fringe wingers Dominic Green and Sergio Torres.

But Posh rarely threatened against negative opponents and goalkeeper Joe Lewis had to produce a brilliant save 12 minutes from time to thwart Dean Green.

Posh struggled on a difficult surface in windy conditions against committed opponents.

Russell Martin and Dominic Green saw free-kicks tipped to safety by Hornchurch 'keeper Dale Brightly, but they were the only threats on his goal.

Hornchurch employed primitive long-ball tactics and apart from the odd goalmouth scramble, they too struggled to create anything.

They did have the ball in the net on 18 minutes, but Green had handled before 'scoring'.

Hornchurch had taken all the plaudits in a dull first-half.

There was no place in the 17-man squad for transfer-listed club captain Micah Hyde.

Youth team players Lewis Webb and Sam Gaughran are among the substitutes.

See Monday's Evening Telegraph for a full match report, comment and photos.

4.10pm: FA Cup: Posh at home in second round.

What do you think of the Posh performance?
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Teams:
Posh: Joe Lewis, Russell Martin, Craig Morgan, Gaby Zakuani, Tom Williams, Sergio Torres, Dean Keates, Paul Coutts, Dominic Green, Aaron Mclean, George Boyd.
Substitutes: James McKeown, Lewis Webb, Sam Gaughran, Craig Mackail-Smith, Shaun Batt, Danny Blanchett, Chris Westwood.

Hornchurch: Dale Brightly, Donny Barnard, Lee Brown, Jon Purdie, Mark Goodfellow, Andy Tomlinson, Frankie Curley, Mark Janney, Kris Lee, Dean Green, Elliott Styles.
Substitutes: Simon Parker, Billy Coyne, Lee Hodges, Ross Wall, Mitchell Stuart-Evans, Jim McFarlane, Michael Bowditch.

Match preview including: Potter couldn't believe that Steven Gerrard wanted his shirt; Posh have lost just 10 times at this stage since 1960, directions to Hornchurch.