If only Sunderland could transfer their cup form to the Premier League, Gus Poyet's side would probably be pushing for Europe rather than striving to stay out of the Championship.

With Poyet having made nine changes to a team battling relegation and already in the Capital One Cup final, the stage looked set for Southampton to canter into the quarter-final. Inexplicably given their comfortable league position, Mauricio Pochettino made six changes and, significantly, a strange performance from his players fell some way short of high octane. Sunderland played quite well but, by semi surrendering, Southampton effectively ushered them towards both the sixth round and mounting end-of-season fixture congestion.

Evidently not entirely heartbroken to , Pochettino was so eager to head for Newcastle airport and a return flight to the south coast that he did not bother addressing the media. "We're not disappointed to be out of the FA Cup," acknowledged Jesús Pérez, his assistant before, hastily, adding the rider, "Just a little bit sad."

Poyet used the tie to experiment with fielding two up front rather than a lone striker and will not be afraid to reprise his 4-1-3-2 formation. "I think I'll call every game a Cup game from now on," he said jokingly. "It's been a good day, we cared about the ball and a few players put themselves back in the frame. I'm sure some of them will play a big part between now and the end of the season."

For Lee Cattermole, a recall offered a chance to try to reclaim his Premier League place from the rested Liam Bridcutt. Sitting just in front of the home defence, Cattermole excelled, placing persistent spokes in Southampton's attacking wheels.

With Andrea Dossena defensively vulnerable at left-back, Cattermole's ability to tidy things up proved invaluable. His effectiveness was such that Oscar Ustari, Poyet's Argentinian goalkeeper, rarely needed to make serious saves.

Despite some very decent cameos from the classy Emanuele Giaccherini – these days largely restricted to the bench and very much the Wearsiders' forgotten £8.6m Italy international – Sunderland struggled to fully stretch the sporadically shaky Kelvin Davis.

True, Poyet's players won several free-kicks in dangerous positions but their execution too often proved wayward.

Ignacio Scocco, the Argentina striker making his debut alongside the intelligent Fabio Borini in the home attack, showed off some lovely touches but appeared to be finding the intensity of it all something of a culture shock after leaving Brazilian football – along with South America's summer – behind last month.

Played in pouring rain and with a crowd of under 17,000 leaving large banks of empty red plastic seats it was turning into a slightly sorry spectacle.

The fact that nearly 43,000 had turned up here for last week's Premier League defeat against Hull speaks volumes about the FA Cup's diminshing allure but at least Craig Gardner's right foot finally raised the tone.

Long-range shooting is very much Gardner's party trick and, after beating Victor Wanyama – searching for form and fitness after a lengthy period out injured – to the ball in the 49th minute, he unleashed a 20-yard shot which arced imperiously before brushing the underside of the bar as it dipped en route to the top corner, leaving Davis scratching thin air.

Gardner's touch may not always be exactly velvet but his well-timed runs from midfield frequently took him behind Pochettino's defence, contributing to increasing visiting discomfort.

Even so the game remained sufficiently open for Southampton to very nearly draw level when the influential Adam Lallana – inexplicably substituted – connected with Nathaniel Clyne's cross only for his flick to fly wide. Then, incredibly, after meeting another Clyne cross, Rickie Lambert missed an absolute sitter, scooping the ball over the bar from three yards.

An unwanted replay averted, Pochettino quite possibly stifled a sigh of relief.