Everton boss Roberto Martinez believes Swansea City have been galvanised since Garry Monk became manager.
Martinez's side knocked the Swans out of the FA Cup with a 3-1 fifth round win at Goodison Park.
It was Monk's first defeat since taking charge but former team-mate Martinez has seen progress in their last few games.
"I think since Garry Monk has taken over everyone is fired up and everyone has a point to prove," Martinez said.
"I've seen them galvanised in the last two games.
"I saw the games previous to that and probably the West Ham game showed a little bit of a pedestrian performance.
"There's a real desire to do well and a real desire to perform well and we all know that this Swansea side is good enough to achieve big things this season.
"They're still involved in the Europa League and with 12 games to go in the league I think the future is very, very bright."
Former Southampton defender Monk was placed in charge for the "foreseeable future" following Michael Laudrup's sacking.
Martinez played alongside and later managed Monk during two spells with the Welsh club and had already backed the appointment of the 34-year-old.
Debutant Lacina Traore, on loan from Monaco, gave Everton the lead just four minutes but Jonathan de Guzman equalised with a powerful header.
But substitute Steven Naismith restored Everton's lead after capitalising on Neil Taylor's backpass before Leighton Baines added a third from the penalty spot.
Martinez's side will face Arsenal in the last eight but the Everton manager praised Swansea's efforts at Goodison Park.
"We controlled the game creating good opportunities and limiting Swansea to very little," Martinez said.
"But you need to give huge credit to the way Swansea played and Garry Monk [showed] a lot of bravery and that allowed it to be an open game."