Mauro Boselli finally started to pay off his £6million transfer fee as Wigan claimed a place in the Carling Cup quarter-finals with 2-0 win over Swansea.
The Argentinian striker struck his first goal since his summer move from Estudiantes as Wigan manager Roberto Martinez secured victory over his former club at the DW Stadium.
Cedric van der Gun should have given the Championship visitors an early lead but Boselli put Wigan ahead in the 51st minute and Ben Watson added a late penalty.
Victory was not as comfortable as the Premier League hosts would have liked but Swansea, backed by a vociferous 5,000-strong travelling faithful and buoyed by their rise to third in the npower Championship, made life difficult throughout.
Van der Gun was sent clear by a Darren Pratley pass but rather than finish himself he crossed for the offside Craig Beattie, and Boselli made him pay when he got on the end of an Antolin Alcaraz pass to finish well in the 51st minute.
Wigan applied the finishing touch in injury time after substitute Charles N'Zogbia was tripped in the area by Andrea Orlandi and Watson struck from the spot.