Robin van Persie led the rout as Arsenal resumed normal service at the Emirates Stadium with a thumping Champions League victory over Porto on Tuesday night.
Gunners boss Arsene Wenger had demanded an emphatic response from his team following their shock 2-1 Barclays Premier League defeat by Hull City on Saturday - and they delivered in irresistible fashion.
Van Persie struck his first goals in European competition for a year, pouncing either side of the interval and displaying strength during a well-taken second.
Emmanuel Adebayor set up the opener for his strike partner and also helped himself to two, the second from the spot after Nicklas Bendtner had been hacked down by Fredy Guarin.
Sloppy finishing prevented Arsenal from further embarrassing the Portuguese champions, who defended shoddily and looked on the brink of collapse at times during the second half.
Theo Walcott was a constant menace, gleefully using the space he was given, but his finishing was not up to the same standard.
Porto, who lost the influential Jose Bosingwa and Ricardo Quaresma during the summer, had never won on English soil in ten previous attempts and looked incapable of ending that run.
After their draw with Dynamo Kiev in their Group G opener, victory sent Arsenal to the top of the pool - and concluded the soul-searching following the horror-show against Hull.
The Gunners were heavily criticised after the result, not least by Wenger himself, but the Frenchman resisted the temptation to axe some of his under-performing stars.
French winger Samir Nasri was the only new face, ending a month-long spell in the treatment room to replace Emmanuel Eboue - who was relegated to the bench.
Nasri had little impact, but the same could not be said for the rest of Arsenal's forward line - who made their presence felt from the start.
Breaking fluidly from their own half, short passing from Persie, Fabregas and Adebayor saw the ball worked across the area to Walcott.
He was stationed on the right and had time to pick his shot, but a smart save from Da Silva Helton saw the effort palmed to safety.
The reactions of Helton saved Porto once again shortly afterwards when van Persie attempted a long-range shot, but then it was Arsenal's turn to mop their brows.
Tomas Costa sped down the right wing and delivered a perfect cross to Cristian Rodriguez, whose diving header hit the ground before deflecting off the bar.
But the effort offered only temporary respite for Porto - who saw van Persie, Walcott and Adebayor miss half-chances.
For all Arsenal's dominance of territory and possession, Porto's speed on the counter meant they could not afford any lapses in concentration.
Lisandro Lopez underlined the point by blasting a beautifully-struck curling shot at the top corner, but a diving Manuel Almunia reacted just in time.
Arsenal remained on top, however, and their perseverance was rewarded with a 30th-minute goal by van Persie.
Adebayor and van Persie combined expertly down the right of the area, creating space for the Togo marksman.
He looked up and delayed his pass to the van Persie, who prodded the ball home.
The Gunners surged further ahead with five minutes of the half remaining when Adebayor leapt above Jorge Rolando to head van Persie's corner towards the ground.
The ball bounced awkwardly for Helton and defender Nelson Benitez, who was stationed on the line - the duo watching as it sailed over their heads.
The second half was just three minutes old when Arsenal added to the score with a surprisingly easy third.
Walcott did the initial damage before the ball found its way to van Persie, who showed strength to fend off Bruno Alves and stab home.
Porto's defence was crumbling, and Walcott should have made it four but missed a sitter from four yards out.
The England forward's pace was proving a constant threat, however, as he marauded down the right wing at will.
Arsenal's fourth arrived when Bendtner, on for van Persie, was brought down by a clumsy tackle from Guarin.
Adebayor stepped up and smashed the penalty home to complete an easy night for the Gunners.
