Graphic: Just one Tonetto - how the action unfolded | Debate: have Arsenal turned the corner?

The only way to prove that this generation of Arsène Wenger’s team are not a group on a perpetual journey of self-improvement who never quite reach their destination is to win something significant, to deliver on their promise.

That hope remains for Arsenal and it is to their credit that they held their nerve not only in the penalty shoot-out, but also after conceding within the first ten minutes and being placed under severe pressure for the rest of the first half.

A sombre chapter in Eduardo da Silva’s storybook return from injury was almost written when Arsenal’s first spot-kick in the shoot-out by the substitute was weak and saved, but Mirko Vucinic’s comically abysmal effort was stopped by Manuel Almunia. A series of excellent kicks took the contest to sudden death, before Max Tonetto lashed his attempt high over the bar to put Arsenal into the quarter-finals and keep a season on the brink of disappointment well and truly alive.

Defeat would have marked the first time that an English club has gone out of the competition to a foreign club since AC Milan overcame Liverpool in the 2007 final, as well as sparking speculation that a premature exit would encourage Arsenal’s key players to seek a fresh start elsewhere in the summer. That can wait.

Arsenal are also still in contention for the FA Cup and look well placed to overhaul Aston Villa and grab a qualifying spot for next season’s Champions League. All the same, we should not be too hasty to proclaim a bright new dawn when there is still a danger it will prove to be false. This was the closest of shaves and some of the early-season defensive flaws that seemed to have been eradicated resurfaced against impressive opponents. However, Wenger is fond of talking about occasions that help his young side to learn and this was certainly an educational experience.

“I’m very proud of the mental strength,” Wenger said. “That is a quality that has been questioned a lot. We have improved tremendously on that front.” He can praise his charges’ spirit and attitude all he likes, but there is little in football more useful than a consistent ability to whack the ball a long way in the opposite direction when it enters your penalty area. Roma’s goal should have been cut out.

Conceding so early was a shock. Coming into this tie, Arsenal had kept ten clean sheets in their past 14 games as part of a 17-match unbeaten run. Cesc Fàbregas and Emmanuel Adebayor were absent through injury, but Kolo Touré returned from his calf problem to partner William Gallas in defence.

The home side were far more depleted through injury and suspension. The good news for Roma was the presence in the starting line-up of Francesco Totti, their talisman and captain who had struggled with a knee injury. His inclusion was a risky choice by Luciano Spalletti, the Roma coach, who perhaps noted the success of Guus Hiddink’s punt on the fitness of Michael Essien in Chelsea’s victory over Juventus the night before. Spalletti was well rewarded, because Totti lasted the whole game and was a source of invention throughout.

The game began brightly for the visiting team and Robin van Persie squandered a good chance in the third minute by delaying a shot and being crowded out. But the sense that Arsenal were unsettled in defence was confirmed in graphic fashion as Roma took the lead. Gallas and Touré merely gawped at Totti’s low left-wing centre as it cut a path across the area, passed through the legs of Rodrigo Taddei and met Juan on the far side of the six-yard box. The defender had ample time to beat Almunia. Roma probably felt the identity of the scorer was apt given their selection problems: Juan was just back from injury. A knock forced him off with less than half an hour gone, but his contribution was telling all the same.

Almunia then saved his side twice in quick succession midway through the half. The goalkeeper beat away Marco Motta’s thumping shot and the rebound eventually fell to Taddei, whose rasping diagonal effort was tipped past a post superbly by the Spaniard. Motta appeared to be hauled down by Gaël Clichy inside the area just before half-time, but the referee, Manuel Enrique Mejuto González, ignored the appeal. There was certainly contact, albeit minimal, as the left back clumsily tried to catch Motta.

Arsenal were sharper after the break, especially going forward, but they were grateful for the poor finishing of an old boy. Júlio Baptista spent the 2006-07 season on loan at Arsenal and scored ten times, but he spurned two fine chances yesterday evening.

Touré should have settled the tie at the end of normal time, heading over from three yards. But to penalties it was — the ultimate test of mental strength and technical ability. Arsenal passed, and passed well.

Roma (4-1-2-2-1): A Doni — M Motta, S Diamoutene, Juan (sub: J Baptista, 38min), J A Riise — M Brighi (sub: V Montella, 120) — D Pizarro, M Tonetto — R Taddei (sub: A Aquilani, 90), M Vucinic — F Totti. Substitutes not used: Artur, Filipe, S Loria, J Menez. Booked: Pizarro, Motta.

Arsenal (4-2-3-1): M Almunia — B Sagna, K Touré, W Gallas, G Clichy — A Diaby, Denilson — E Eboué (sub: Walcott, 75), S Nasri, N Bendtner (sub: Eduardo da Silva, 85) — R van Persie. Substitutes not used: L Fabianski, C Vela, A Song, J Djourou, K Gibbs. Booked: Diaby.

Referee: M E Mejuto González (Spain).