Comfortable win for Portuguese giants...
Brazilian duo Hulk and Fernando did the damage for the hosts as the big striker bagged a hat-trick from dead balls while promising Belgian youngster Jelle Vossen netted twice for the Belgian side.
The visitors gave themselves a slender lifeline midway through the first half when Vossen reacted quickest to prod Dugary Ndabashinze's low cross past Beto into the top corner to fire Genk in front.
Hulk had the opportunity to restore parity straight from the restart when Genk 'keeper Koteles Laszlo tumbled the big striker inside the box but the shot-stopper atoned for his error by saving the spot kick to give the Belgian side further encouragement.
Those slim hopes of a fightback were dashed nine minutes before the break however when Hulk stepped up to smash a 30-yard free kick beyond the hapless Koteles to make it 1-1 on the night and 4-1 on aggregate.
Porto gradually took control of proceedings and grabbed the lead rather fortuitously eight minutes after the restart when Fernando caught Koteles napping with a 25-yard drive to fire the hosts into the lead.
Three minutes later the visitors had pulled themselves level once more as the lively Vossen again reacting swiftly to nod home another fine cross from Ndabashinze but their resistance proved short lived as the hosts regained the lead within a matter of minutes.
Dimitri Daeseleire committed a needless foul on Porto midfielder Moutinho just inside the penalty box and Hulk once again stepped up to take the resulting spot kick, this time making no mistake sending the 'keeper the wrong way.
Shortly after the hour mark the 24-year-old completed his hat-trick with his second 30-yard free kick of the night. The thunderous drive was well struck but the goalkeeper completed a night of mixed fortunes with another personal error, as he should have got a hand on Hulk's effort.
The final half hour was a stroll for the hosts, who make their return to Europe's silver medal competition for the first time since they won the UEFA Cup under the stewardship of Jose Mourinho in 2003.