Airdrie's five-game unbeaten run in Scottish League One came to an end with a 3-1 defeat to Peterhead.Ryan Strachan headed home Rory McAllister's cross to give the visitors a sixth-minute lead but Scott Fraser quickly equalised with a low, left-foot finish from inside the penalty area.There were chances at both ends shortly afterwards, with Bryan Prunty's header forcing a parrying save from Peterhead goalkeeper Graeme Smith and Dean Cowie heading the ball narrowly wide.But the Blue Toon hurt the hosts with two goals either side of half-time. An own goal from Marc Fitzpatrick after 42 minutes restored Peterhead's lead, before James Stevenson's free-kick two minutes after the restart gave Jim McInally's men a two-goal cushion.Airdrie had a late chance near the end but Prunty fired over the crossbar.