Nacho Monreal and Alex Iwobi stretched Arsenal's winning run to four consecutive games in all competitions as Alexis Sanchez dazzled in the 2-0 Premier League victory over Brighton and Hove Albion.

Monreal's opening goal arrived after Alexandre Lacazette was denied by the post during the early stages for Arsene Wenger's side, although Solly March was similarly close to a Brighton equaliser before half-time.

Sanchez took centre stage after the break and set up Iwobi to double the Gunners' advantage with a sublime backheel.

The 28-year-old forward was unable was unable to claim a maiden Premier League goal of the season but his performance offered a vindication of Wenger's hardball transfer window tactics, which left Sanchez unable to complete a deadline-day move to Manchester City.

Arsenal are unbeaten in seven matches since their 4-0 humbling at Liverpool in August and are now level on points with defending champions Chelsea in fourth.

Lacazette unleashed a rasping 25-yard drive against the post inside two minutes and Arsenal dominated the opening exchanges with pleasingly slick interplay.

Clear-cut chances were not forthcoming, however, and it took a more robust approach to bring about the 16th-minute opener.

Shkodran Mustafi had an effort blocked following a set piece on the right and Hector Bellerin's follow-up also cannoned into a Brighton body before Monreal rifled in for a first Premier League goal since March 2013.

Brighton had limited opportunities to exert themselves as an attacking force but March rattled the upright when a free-kick was laid into his path after 28 minutes, with Petr Cech helpless. Lewis Dunk was unable to direct his follow-up volley on target.

A scramble in the Arsenal penalty area opened up into a swift counter-attack for the hosts three minutes before the break. Lacazette, Alexis Sanchez, Bellerin and Sead Kolasinac were all involved before Albion goalkeeper Mathew Ryan saved with his boot from Aaron Ramsey.

Sanchez turned in a virtuoso performance after half-time, with his standout moment of brilliance making the points safe in the 56th minute.

The Chile star collected Ramsey's pass in the area and moved towards the edge of the box with his back to goal, only to unfurl a delightful backheel.

It meant Iwobi received the ball with ample time to thump into the top corner as the Brighton defence headed off in the wrong direction.

With the result all but settled, the game became a means for Sanchez get the goal his efforts deserved.

He would ultimately be frustrated by Dunk clearing off the line after Ryan took the pace off a 61st-minute effort, while he dragged a later effort wide.

Dunk, who performed tirelessly at the back for Brighton and produced a brilliant recovery tackle on Lacazette, brought down Sanchez at the end of a menacing run, only for the former Barcelona man to swipe the free-kick over.

He pulled his shirt over his face in frustration – an entirely different emotion to that experienced by Wenger and the Arsenal supporters still able to watch Sanchez in their colours when this mood grabs him.