Nicklas Bendtner struck a hat-trick as Arsenal outclassed Porto to overturn a first-leg deficit with ease and clinch a place in the last eight of the Champions League. Bendtner - heavily criticised after a succession of misses in Saturday's win against Burnley - scored twice in the first half to wipe out the 2-1 lead Porto were protecting from the first game in Portugal. Andrey Arshavin was instrumental in both goals as Bendtner added the final flourishes to Arsenal's flowing attacking moves that enabled them to take control almost instantly. Porto applied brief pressure after the interval, with Manuel Almunia saving from Falcao, but Arsenal completed the formalities and cruised into the quarter-finals with two superb goals inside three minutes just after the hour. Samir Nasri, taking on Cesc Fabregas' midfield mantle in the absence of Arsenal's inspirational captain through injury, embarked on a weaving, angled solo run that took him past a succession of Porto defenders to score. Substitute Emmanuel Eboue quickly added the fourth as Arsenal launched a sweeping counter-attack from a Porto corner, Arshavin again making life easy for his team-mate to go around Helton and score. Bendtner crowned a night of personal glory and an emphatic victory for Arsenal when he scored from the spot with virtually the last kick of the game after Eboue was hauled down. Porto, a short spell at the start of the second half aside, were flimsy opposition. Greater challenges will lie ahead for Arsene Wenger's side - but the victory margin was a fair reflection on their superiority in front of an elated Emirates gallery. Wenger used his programme notes to launch an impassioned defence of Theo Walcott following criticism of his disappointing performance for England against Egypt - but decided to start with him on the bench. Arsenal hardly missed him in a turbo-charged start that established the foundations for a first 45 minutes that saw them in charge of the tie by the interval. Arshavin's header had already brought a fine save from Helton at his near post before Bendtner put his wayward weekend finishing behind him to give Arsenal the lead after 10 minutes. Nasri's pass sent Arshavin through, and when Nuno Coelho collided with Helton as he challenged the Russian, Bendtner was lurking to steer home the loose ball. And it was Arshavin's creativity that unlocked Porto again and set Bendtner up for his second 15 minutes later. He tormented Porto with some trademark sleight of foot before providing Bendtner with the easiest of chances. Porto had shown some threat on the break, but the real danger was coming from Arsenal and Arshavin should have tightened their grip on the game 12 minutes before half-time, only to fire carelessly over the top of an open goal after fine work by Nasri. As Arsenal continued to carve open the Porto defence, Helton twice came to his side's rescue as he saved low down from Bendtner, then dived at his post to push out Abou Diaby's header. Porto had their best chance after 54 minutes when Hulk set up Falcao, but his finish was straight at Almunia, who held on at the second attempt. Nasri then made two crucial contributions at either end of the pitch to ensure Arsenal's safe passage into the last eight. He distinguished himself in defence by clearing Porto substitute Cristian Rodriguez's header off the line, then unveiled a moment of supreme skill to wrap up Arsenal's win after 63 minutes. He slalomed in from the right flank, twisting and turning past three Porto defenders to flash a finish across Helton into the far corner, and Eboue was able to put further polish on Arsenal's performance when he added the fourth three minutes later. Arsenal have been victims of swift counter attacks from Everton, Manchester United and Chelsea in recent weeks, but this time the boot was on the other foot as Arshavin led the charge from a Porto corner to play in Eboue, who rounded Helton to score. And Bendtner was not to be denied a first senior hat-trick when Arsenal were awarded a penalty with only seconds left. He snatched the ball and slid his penalty past Helton to provide the perfect finale to a wonderful night for Wenger's side. Source: BBC