Alexis Sanchez on the scoresheet as Arsenal come from behind to win

Arsenal beat FC Köln 3-1 in their opening Group H fixture of the Europa League at the Emirates Stadium.

The match was delayed by an hour as thousands of ticketless FC Koln supporters turned up outside the ground.

Whilst others who had managed to buy tickets for the home sections were involved in scuffles with stewards inside the ground after the gates opened.

It’s estimated that around 20,000 FC Koln fans made the trip to London, despite the club only receiving an official ticket allocation of 2,900.

Arsene Wenger made nine changes to the starting eleven who took the field against AFC Bournemouth on Saturday.

Only Hector Bellerin and Nacho Monreal retained their places.

The Gunners looked disjointed from the start of the match and struggled to inject any fluency into their play.

The Geissböcke (The Billy Goats) were back in European competition for the first time in 25 years, and made up for lost time in the 9th minute by taking the lead when Jhon Cordoba lobbed fellow Colombian David Ospina from 40 yards..

Theo Walcott and Olivier Giroud spurned chances to get Arsenal back on level terms in the first half.

At the break it seemed that the Gunners were going to continue their recent poor home record against German teams.

Before tonight they had lost five of their last seven home matches against German teams.

A half time substitution though turned the tide for the Gunners.

Sead Kolasinac replaced Rob Holding, who had endured a torrid first half.

Arsene Wenger abandoned the three at the back-formation. Switching to a flat back four, with Kolasinac slotting in at left back and Ainsley Maitland-Niles moving to central midfield.

The changes paid off in the 49th minute with Kolasinac equalising with a thumping volley past keeper Timo Horn.

Alexis Sanchez then put Arsenal ahead in the 67th minute after a solo run and curling shot. It was his first goal of the season.

Sanchez has had a stuttering start to the season with a £60m move to Manchester City falling through on transfer deadline day.

The Chilean was Arsenal’s top scorer last season with 30 goals in all competitions.

Hector Bellerin wrapped up the win in the 81st minute, when he followed up after Horn had spilled a shot from Walcott.

Jack Wilshere made a brief substitute cameo appearance. It was his first Arsenal appearance since August 2016.

In Group H’s other game tonight, Red Star Belgrade drew 1-1 against BATE Borisov.

Arsenal: Ospina 6, Bellerin 7, Maitland-Niles 6, Mertesacker 6, Holding 4 (Kolasinac), Elneny 6, Iwobi 8 (Wilshere), Sanchez 7, Walcott (Nelson) 5, Giroud 6