Tottenham are off to Wembley for the Carling Cup final after hammering Arsenal 5-1 (6-2 on aggregate) in their semi-final.
Goals from Jermaine Jenas, Nicklas Bendtner (own goal), Robbie Keane, Aaron Lennon and Steed Malbranque earnt Spurs the victory with substitute Emmanuel Adebayor grabbing a consolation for the Gunners.
Betfred are facing a £500,000 payout after Spurs' victory.
"We were hoping that the Gunners would have blasted the Spurs defence apart." said Betfred spokesman Dave Metcalf.
"It was the worst result imaginable for us as we have laid Spurs heavily at 4-1 to win the competition outright, including one single bet of £50,000 to win £200,000. If Spurs go on to land the Carling Cup it will be us who are needing a few drinks to drown our sorrows!, " added Dave.