Champions League -- Arsenal cruise into last eight
And Bendtner, who came under fire at the weekend for missing several chances against Burnley, secured his first career treble from the penalty spot in injury-time.
It was the most emphatic way for the tall Dane to answer his critics: not only demonstrating again the art of being in the right place at the right time, but also finishing almost every opportunity that fell his way.
Yet there were greater stars shining for the Gunners on an uplifting night in North London. Mercurial Russian Andrei Arshavin put the opening strikes on a plate as well as the fourth for Eboue, while Nasri had a hand in the first and stunned the 60,000 crowd with a wonderful run and strike to seal the tie.
Arshavin could have opened the scoring with a header from a Bacary Sagna cross only eight minutes in, Helton providing the first of many impressive saves despite the unflattering scoreline.
A minute later it was 1-0. Arshavin wandered back from an offside position as Manuel Almunia launched a ball forward from outside his box, climbed to win a header back to Nasri and spun off; when the inevitable through-ball came a three-way tussle between Arshavin, Helton and Jorge Fucile saw the ball run loose - and Bendtner was lurking to finish.
Arshavin likes to come inside and curl into the corner, but Porto, well aware of this, showed him the outside throughout. Undeterred he powered to the by-line and squared out of Helton reach, but his cross beat everybody.
Three minutes on, in the 25th, he did it again. Right-back Fucile turned in from the touchline, frustrated that the ball would not run out, and his poor ball was gathered by the Russian who ambled through two weak tackles before delivering the same run and cross - and this time Bendtner arrived with perfect timing to sidefoot home.
Even great players have lapses, and so it proved with Arshavin guilty of firing over with an open goal at his mercy following a deep cross by Sagna.
Porto began to attack more frequently, with Hulk disappointing with a near-post cross when Ruben Micael was unmarked for the pull-back.
Helton kept his side in the tie with a pair of saves in the corner from Bendtner and
Arsene Wenger was angry on the touchline as Falcao began to make inroads in attack and Jesualdo Ferreira's men won a succession of corners.
Almunia blocked a first-time Falcao strike and Nasri cleared off the line following a Rodriguez header while at the other end Arshavin forced Helton into a desperate double save with a lovely volley from outside the area.
On 63 minutes the tie was effectively sealed. Nasri turned away from goal on the right touchline, looking for a pass, and seeing none turned back again; he shimmied his way past Raul Meireles, Bruno Alves and Rodriguez before rocketing a low shot in off the far post from a tight angle.
Arsenal added another less than three minutes later when Arshavin brushed off Fucile following an away corner, ran 40 yards and fed an ideal ball onwards for the intelligent run of Eboue, who had replaced Tomas Rosicky.
With Helton rushing out, the Ivorian took the ball to one side and finished past the despairing dive of a defender.
The Gunners were on easy street from there on in, their fans cheering their keep-ball strategy and Falcao left chasing shadows every 10 minutes when a ball came near him.
The match was given a glorious ending when Eboue raced into the box, drawing a tackle from behind from the unfortunate Fucile.
Helton went the right way but Bendtner, whose name had been sung by the home fans throughout the second half, responded to a renewed chant by dispatching it firmly into his left-hand bottom corner.