Peterhead produced a stunning second-half performance to win 4-1 and end East Stirling's 100 per cent record.
The League Two leaders looked set to continue their impressive start to the campaign when Paul Quinn converted from the penalty spot in the fifth minute after Kevin Turner was brought down by Ryan McGeever.
East Stirling remained in front until just before the hour. Jordan Brown's right-footed finish was the first of four goals in 23 minutes for the visitors.
James Redman finished low past Grant Hay to put Peterhead in front, before Stephen O'Neill gave them a cushion when he swept home Rory McAllister's long ball.
McGeever's left-footed effort completed an emphatic first win of the season for Peterhead.