Arsenal v Barcelona, Champions League last 16, first leg, Emirates Stadium, 7.45pm, ITV1

CAMP Nou, 6 April 2010. Nicklas Bendtner gives Arsenal the lead in the cathedral of Catalan football and Arsenal look set to reach the Champions League semi-finals. We all know what happened next.

Lionel Messi scored within two minutes, added a second and completed a sublime hat-trick before half-time. Arsenal were stunned, outplayed by just one player, trailing 5-3 on aggregate and on their way out. In the second half they could not respond, while Messi underlined his mastery and added a late fourth.

On Wednesday night, Barcelona and Arsenal meet again, when the Spanish champions come to the Emirates in the first leg of the Champions League last 16 tie. And the bad news is that Barcelona 2011 are looking a lot better than their 2010 version.

A glance at the La Liga table confirms it, and should be enough to set fear into Arsenal hearts. Barcelona lead their great rivals Real Madrid by seven points having won 20 out of 23 games, drawing one and losing just once so far, to struggling Hercules way back in September.

They have scored a hefty 70 league goals, and have conceded just 11, with 10 wins out of 10 so away from home in the league until they drew 1-1 at Sporting Gijon on Saturday.

Their progress in cup competitions has also been serene – they slaughtered Almeria 8-0 on aggregate (after also beating them 8-0 in a league game) to set up a Copa del Rey final with Real Madrid in April.

Barca have also already won the Spanish Super Cup by beating Sevilla 5-3 on aggregate, even after conceding a 3-1 lead following the first leg, easily overturned with a 4-0 thumping in Camp Nou.

If Arsene Wenger is looking for weaknesses in that record, there are very few. But in the group stage of the Champions League, Josep Guardiola’s side were not quite so impressive.

While Panithinaikos, FC Copenhagen and the Russians of Rubin Kazan were all beaten on Spanish soil, 1-1 draws in Russia and Denmark were rare slip-ups in their imperious season to date.

Nonetheless they remain the overwhelming favourites in this tie, and even to repeat their 2009 quadruple, something that proved beyond them last season when they were defeated by Jose Mourinho’s Inter Milan in the Champions League semi-finals, and also by Sevilla in the Copa del Rey.

Those two eliminations remain the only blotches on Guardiola’s magnificent record since taking the reins from Frank Rijkaard in the summer of 2008. Arsenal will be aiming to inflict a third over the coming weeks, with the second leg in Spain on 8 March.

Clearly, it is going to be a tough ask. Barca have strengthened since last season’s meetings, shipping out Swedish striker Zlatan Ibrahimovic (scorer of both goals in the 2-2 first-leg draw at the Emirates) and Yaya Toure and replacing them with Spain’s World Cup hero, David Villa, a �34m acquisition from Valencia, and Javier Mascherano from Liverpool.

In January, they also snapped up the highly-rated Dutchman Ibrahim Afellay from PSV Eindhoven. However the signing they really desire – Arsenal’s captain Cesc Fabregas – still eludes them, even if the popular theory is now that, after last year’s failed bid, Barca will finally prise their former player away from the Emirates this summer.

Villa completes a diminutive but highly potent strike trio alongside Messi and the latest product of the club’s infamous La Masia youth academy, Pedro.

However it is the magical midfield duo of Andres Iniesta and Xavi who are still the heartbeat of this side, just as they were for Spain in their global conquest in South Africa last summer, with Sergio Busquets, superb in that 4-1 win over Arsenal last April, in the holding, Alex Song type role behind them.

Much like Arsenal, defence is supposed to be Barca’s weakness, but the statistics do not back that up, and they have conceded just four goals away from home in La Liga.

At home, as Arsenal discovered last season, they remain irresistible, so the Gunners will know that gaining some kind of first-leg lead is imperative on Wednesday night.

As Sevilla found out in the Super Cup, however, even 3-0 wasn’t enough. Arsenal would be ecstatic with a score like that but, in truth, equally pleased with any kind of victory over the team who are fairly accepted, everywhere outside Madrid, as the best in the world.