Douglas Alexander, Labour's shadow foreign secretary and an MP for more than a decade, has been thrashed by Mhairi Black of the SNP.
She got 50.9% of the vote to his 38.6%, a swing of more than 30%.
Alexander had held the Paisley and Renfrewshire South seat since its creation in 2005, and won a 59.6% share of the vote in the 2010 election.