A glorious 27th-minute strike from Nathan Dyer, on loan from Southampton, and a penalty by Jason Scotland left Pompey's cup defence in tatters.

Swansea, who sit ninth in the Coca-Cola Championship, played passing football throughout and Martinez was thrilled the upset was completed in style.

"I'm delighted that we were able to come to a Premier League environment and be ourselves," he said.

"If you look at our form in the Championship over the last six games, we've been at that level and I'm glad we've stayed there.

"We had no Championship experience at the start of the season and it was bit of an eye-opener when we came into the league.

"For me, I'm extremely proud of the way the players dictated things from the beginning against Portsmouth.

"There's room for improvement but the average age of the players is 25-26 and there's huge hunger in the team.

"They want to win games for Swansea and that's why our dominance today didn't surprise me.

"It would be very foolish to say we can go on to reach the final but I know we can improve on this. This is a fantastic result."

Martinez hailed an outstanding display by Dyer - jeered throughout by the home fans because of his Southampton connection - that was capped by a clinical finish of Scotland's astute lob into the area.

"Nathan was a threat all of the time. Mentally he'd run out of gas at the end, as you'd expect, but he will fulfil his potential," said Martinez.

"I've always said he has to play in the Premier League and slowly he's getting there.

"He's had a few problems in the past. He's desperate to enjoy his football. He's a lively character in the dressing room and is fresh.

"The crowd reaction maybe added an extra spice to his game, but the real difference today was his hunger.

"He's learned from his mistakes in the past and is ready to fulfil his potential."

Swansea dominated the first half but were forced to weather Pompey's attempted fightback after the interval.

Keeper Dimitrios Konstantopoulos starred as the home side were kept at bay and Pompey boss Tony Adams had no complaints with the result.

"In the first half we were outplayed and outfought," said the former England skipper.

"I did warn the players we were up against a very good Swansea team who like to pass the ball and that we would be in trouble if we weren't prepared.

"Sadly, I was proved right. Without that fight you go out of this competition.

"We didn't deserve to be 2-0 down at half-time but we didn't play well in the first half either. We were very poor.

"It's disappointing to go out of the FA Cup, no matter what round it is.

"You have to put defeats like this to bed as quickly as possible."

ends