Brighton manager Gus Poyet was left to rue a disappointing day at the office after his side lost 2-0 at Northampton in the Carling Cup first round.
Northampton youngster Michael Jacobs grabbed the opening goal on his full debut, cutting inside before beating Michael Poke from 15 yards.
Billy McKay then doubled the Cobblers` advantage over their League One opponents with a diving header.
Albion has Matt Sparrow sent off and lost midfielder Alan Navarro to injury, with Poyet saying: "It wasn't a great day for us, especially with the sending off of Matt Sparrow and the injury to Alan Navarro.
"We could lose Matt for three games and the injury to Alan doesn't look good. We will have to assess the injury but he's a key player for us and that could be a big blow."
He added: "I'm not looking for excuses but the first goal wasn't even a chance. You have to deal with that and the goal gave Northampton a great opportunity in the game."