Damian Martinez - 7/10
The 21-year-old gave a good account of himself, making a number of saves and not making anything easy for Benfica. Was not troubled all that often and couldn't have done anything about Nicolas Gaitan's goal.
Hector Bellerin - 9/10
A surprise star, the Arsenal youngster absolutely shone against Benfica, providing a sensational assist for the Gunners' second goal and causing the Portuguese side problems all day long. Ever since his appearances for Arsenal's NextGen side, Bellerin has got better and better. Could this be his season?
Calum Chambers 7/10
The new Arsenal signing had no trouble at centre-back and was barely tested.
Nacho Monreal - 6/10
One of Arsenal's more underwhelming performers, Monreal was booked early on for a bad tackle and didn't contribute too much going forward.
Kieran Gibbs - 7/10
Was remarkably calm at the back for the Gunners, effortlessly dealing with most things that came his way.
Mathieu Flamini - 7/10
The Frenchman did his job defensively and kept a clean sheet. Perhaps somewhat coincidentally, Benfica scored moments after he came off.
Joel Campbell - 8/10
Criticised for a sloppy start after getting into great positions but making the wrong choices early on. From thereon in, though, it was plain sailing as Campbell both scored and registered an assist. Overall, a solid display from the Costa Rican.
Aaron Ramsey - 9/10
Ramsey was typically superb for the first goal to set Yaya Sanogo up (and also for Sanogo's fourth) and produced nothing less than his usual quality at all other times. Came off midway through the second half after a brilliant shift.
Tomas Rosicky - 7/10
A good run-out for the Czech, who kept up with the pace of the game well.
Alex Oxlade-Chamberlain - 7/10
Contributed to his side's blistering first-half performance but was inevitably outshone by the likes of Ramsey and co. Came off at half-time.
Yaya Sanogo - 10/10
Missed chances but will be delighted to have got on the scoresheet in the first half. And what followed was a thing of dreams for the Arsenal man as he netted twice more before the break. A first Sanogo hat-trick for the Gunners - which was then followed by another goal in the second half!
Santi Cazorla - 7/10
Was on set-piece duty for the second half and enjoyed a good run-out.
Jack Wilshere - 6/10
Helped keep things steady for Arsenal as they normalised the pace of the game after the frantic first half.
Mikel Arteta - 6/10
Like Wilshere, kept the Gunners ticking.
Francis Coquelin - 7/10
Came on late on and hit the post.
Chuba Akpom - 6/10
Also troubled Benfica in the final third.
Alexis Sanchez - 6/10
This game was never about what Sanchez would do on the pitch - but simply getting him out there. He came on in the 73rd minute to a rousing ovation from the Arsenal fans.
Ignasi Miquel - 7/10
Impressed and hit the bar with a header.