Roma scored three at the Camp Nou but their chances of reaching a first Champions League semi-final since 1984 are slim. This time it was not Lionel Messi who scored and, although Luis Suárez ended his year-long wait for a Champions League goal, it was two own goals that really enabled Barcelona to take a significant step forward.

It is not yet definitive after Edin Dzeko’s late strike at the right end for Roma. Daniele De Rossi and Kostas Manolas both put past their own goalkeeper before Gerard Piqué added a third for Barça and, although Dzeko momentarily brought hope for the visitors, Suárez’s poacher’s goal in the closing stages should make this scoreline sufficient for Barça to progress.

The route Barcelona took to get to 4-1 was unexpected and the performance did not always convince, while a hint of fatigue will be a concern. “We’re at a time of the season when rests are not permitted,” Ernesto Valverde said. Barcelona had 19 shots, Roma 13. Asked if the result was hard on Roma, Eusebio Di Francesco replied: “Yes. It was unfair.”

Posters went up around Barcelona welcoming the Romans and warning them that 100,000 gladiators awaited. They was not so many nor were they so fierce, and at times the quarter-final matched the flatness of the atmosphere.

“Why not be optimistic?” Di Francesco had asked. There is little room for optimism now for the Roma manager but even without Radja Nainggolan his side began on the front foot and there were periods when they threatened. “They’re a good side who can make things difficult,” Valverde said.

Barcelona were uneasy, hurried, the ball given away, and nine minutes in Roma appealed for a penalty when Dzeko was bundled over. The challenge from behind was clumsy at best from Nélson Semedo. He had been included to give the defensive security Valverde wanted as he sought a clean sheet but that was rarely apparent as bit by bit Barcelona took control. Messi’s and Suárez had efforts before Ivan Rakitic hit the post and sent a shot over the bar. Alisson Becker then dived to deny Messi just before the half-hour.

The pressure was building, Messi running at Roma, although a clear route through the accumulation of bodies proved elusive until De Rossi inadvertently provided it, defecting the ball into the corner as he tried to cut out a pass. It was the fourth own goal Barcelona have “scored” in the competition – the highest total for any team in 15 years.

Barça’s Samuel Umtiti tripped Lorenzo Pellegrini, who fell into the area, but the free-kick was given on the edge. Pellegrini hit the shot against the wall and the stadium, largely quiet up to that point, found its voice – as if the goal, and the threat, had awoken the home fans. The first half ended with Messi hitting a free‑kick into the wall and seeing another shot blocked; the second began with Roma missing a wonderful opportunity when, six yards out at the far post, Diego Perotti headed wide.

Again, Barcelona looked ill at ease, Umtiti was almost caught by Alessandro Florenzi as he tried to control close to goal but Barça soon had two more goals.

Their second, like the first, was fortunate. Rakitic’s superb ball hit Manolas, hit the post, bounced back through the legs of Umititi, hit Manolas on the knee and rebounded into the net. Barcelona had been given their second and four minutes later they got one of their own when Suárez’s shot was pushed away by Alisson, straight to Piqué, who side-footed home from a couple of yards out.

Roma got the goal they needed. Marc-André ter Stegen got himself into trouble then got himself out of it again, losing the ball as he tried to turn deep into his own area. Stephan El Shaarawy clipped it to Gregoire Defrel, who fired goalwards only to find Ter Stegen flying back to save. There was applause and apologies, too.

A moment later, they were clapping again when Ter Stegen dived to save Perotti’s curler. And then, Barcelona were caught. Perotti delivered for Dzeko to control and score. Roma had a goal of their own at last but with three minutes to go Suárez made it four with his first Champions League goal of the season.