Napoli are seven points adrift of the Serie A Champions League places but their chances of reaching Europe's elite competition by winning its second-tier cousin look strong after they crushed the German side in their quarter-final first leg.
The other three ties are in the balance with holders Sevilla coming back to beat Zenit St Petersburg 2-1 in Spain, Dynamo Kiev conceding late in a 1-1 home draw with Fiorentina and Club Bruges drawing 0-0 with Dnipro Dnipropetrovsk.
Sevilla's hopes of retaining their title looked under threat when Aleksandr Ryazantsev lashed home for the visitors but Carlos Bacca equalised and fellow substitute Denis Suarez grabbed an 88th-minute winner with an exquisite volley.
Zenit, though, will fancy their chances of overturning the deficit in next Thursday's return leg, keeping alive the possibility of a final between clubs from Russia and Ukraine amid simmering political tensions between the two countries.
Dnipro will be the happier of the two Ukrainian sides left in the competition and need only to win at home against Bruges to progress, while their compatriots face a tougher challenge.
Kiev took the lead against Fiorentina through Jeremain Lens's deflected effort after 36 minutes and led until the second minute of stoppage time when Khouma Babacar equalised with an overhead kick to snatch a crucial away goal.
Wolfsburg might have fancied their chances against Benitez's stuttering Napoli outfit having dispatched another Serie A side Inter Milan comprehensively in the last round, but when it comes to Europe the Spanish coach is a canny operator.
A European champion with Liverpool in 2005 and seeking to become the second man after Giovanni Trapattoni to win the Europa League trophy for a third time, Benitez knows how to approach the cut and thrust of continental knockout competition.
The manner in which Napoli took the lead was controversial, however, with Gonzalo Higuain controlling a lofted through ball with his arm before firing home after 15 minutes for his fifth goal in his last five Europa League appearances.
The Argentina striker then set up Hamsik with a delightful crossfield through ball which the Slovakian walloped home eight minutes later before adding a third 19 minutes after the break.
Substitute Manolo Gabbiadini headed in under the trailing foot of Wolfsburg keeper Diego Benaglio to effectively kill the tie, before Nicklas Bendtner grabbed a late consolation.
Things looked to be going awry for holders Sevilla when Ryazantsev fired home at the second attempt to hand Zenit the lead after 29 minutes, but their hopes of overturning a woeful record against Spanish clubs fell apart late in the second half.
Zenit, who have won only twice in 15 games against Spanish opponents and are without a victory in their last eight against La Liga teams, were pegged back after 73 minutes when Bacca powered home a header.
The comeback was completed when Suarez produced a feat of clinical technique to bury a stunning volley from the edge of the area with two minutes remaining.
There was also late drama in Ukraine where Dynamo Kiev were hoping to meet the Fiorentina side who have struggled recently in Serie A rather than the swashbuckling Europa League version who put paid to Tottenham Hotspur and AS Roma in the last two rounds.
It all seemed to be going to plan when Lens's shot from the edge of the area took a wicked deflection and looped into the net over Fiore keeper Neto in the first half.
Babacar's late acrobatics, however, meant that the two sides return to Florence in a week's time with the scores level and the Italians carrying a precious away goal. – Reuters
Original source: Napoli closing in on Europa League semis