Milik, Mertens star as Napoli outclass Benfica

Milik, signed as a replacement for Juventus striker Gonzalo Higuain, headed a brace in a 2-1 come-from-behind win at Dinamo Kiev a fortnight ago to hand coach Maurizio Sarri his maiden win in the competition.

Sarri had warned of the threat posed by the Portuguese champions in the build-up.

But despite glimpses of promise and a brilliant consolation goal by 19-year-old sensation Goncalo Guedes, the visitors were no match for last season's Serie A runners-up on their way to seeing a 17-match unbeaten run come to an end.

Napoli fans had not been treated to Champions League football since 2013, when a side led by Walter Mazzarri were eliminated behind Borussia Dortmund and Arsenal.

And after a one-sided opening half, the San Paolo stadium was not left disappointed.

Twice in the opening minute Milik pounced on lobs over the defence, the Pole coming closest when he toe-poked a tame shot at Julio Cesar after just 20 seconds.

Benfica bared their teeth within five minutes but Kostas Mitroglou's close-range snapshot was parried by Pepe Reina, who then saved the Greek striker's drive from the edge of the area minutes later.

The move saw Raul Albiol pull up injured for the hosts, prompting Sarri to hand Serbian Nikola Maksimovic an unexpected debut off the bench.

A lengthy period of Benfica possession prompted a chorus of jeers but once Andre Almeida had skied a speculative effort over Reina's bar, Napoli's formidable midfield moved up a gear.

Jose Callejon was poised to pull the trigger on Dries Mertens's superb cross-field ball until Alex Grimaldo's timely intervention deep on the right.

It gave Napoli a corner, and from Faouzi Ghoulam's delivery Marek Hamsik was on hand at the near post to glance a header past former Inter Milan 'keeper Cesar.

Cesar, who won the treble with Inter in 2010, admitted Tuesday he had no recollection of winning at the San Paolo in seven successful years with the Nerazzurri.

Benfica coach Rui Vitoria must have wished he had taken the keeper's admission as a portent as Napoli hit three quick-fire goals in succession after the restart.

When Lisandro Lopez hauled down Mertens just inside the area, the Belgian's superb curling free kick from outside the area left Cesar rooted to the spot.

Three minutes later, Milik stepped up to score from the spot after the 'keeper's foul on Callejon.

Vitoria replaced central midfielder Andrea Horta with Eduardo Salvio, and minutes later Napoli stretched their lead to 4-0 after Cesar spilled Callejon's right wing cross to see Mertens convert at the second attempt.

It was the first time in Napoli's history they had scored four goals in major European competition, and the score would have been more emphatic without some slack defending in the final 20 minutes.

Guedes replaced Carillo on 67 minutes and only three minutes later pounced on Jorginho's poor pass back to round Reina and fire into the roof of the net from a tight angle.

Napoli tired in the final five minutes and when Salvio's pace took him past Ghoulam, a soft touch saw him beat Reina.

It was Benfica's second consolation of the night but might not be enough to rescue a group campaign that started with a 1-1 draw at home to Besiktas.