Arsenal analysis: Alexis Sanchez delivers as Arsene Wenger's Gunners dig in to set up Chelsea FA Cup Final

Arsenal will play London rivals Chelsea in the FA Cup final on May 27 after beating Manchester City 2-1 following extra time in the semi-final at Wembley on Sunday.

Arsenal had to come from behind after Sergio Aguero scored his 30th goal of the season for City in the 63rd minute, racing away on to a pass from Yaya Toure.

Spanish international Nacho Monreal equalised nine minutes later, from a cross by Arsenal's other wing back Alex Oxlade-Chamberlain.

In the 11th minute of extra time, just after Aguero was taken off, Alexis Sanchez scored the winner to send Arsene Wenger into another FA Cup Final.

James Olley was at Wembley to assess the key talking points...

Wenger could yet finish the season on a high

It remains to be seen whether Arsene Wenger extends his 21-year stay at Arsenal but whatever happens, he now has the chance to finish a difficult campaign with a third trophy in four years.

Remarkably, it is Wenger’s eighth Final and he now has the chance to surpass George Ramsay as the most successful manager in the competition’s history (they are currently tied on six wins each).

Victory in the FA Cup Final against Chelsea will not appease those supporters who believe Wenger is incapable of ensuring Arsenal compete for the biggest prizes, but the prospect of another Wembley trip will help lighten the mood around London Colney after a troubled period.

Some would see success against Chelsea as the perfect way for Wenger to go out; others may consider it evidence he should continue. Either way, the immediate picture just got a little brighter.

Three at the back is not a one-off for Wenger

Wenger played down the prospect of using a three-man defence on a long-term basis after using the system for the first time in 20 years at Middlesbrough on Monday yet Arsenal adopted the same shape here.

Despite an unconvincing showing against the worst attack in the league, Wenger fielded the same starting line-up and opted to fight City on the counter-attack rather than go toe-to-toe.

It was a risky proposition given City’s talented playmakers but Arsenal gradually grew in strength and confidence as the match wore on, lasting the pace better than City whose players notably fatigued.

Arsenal show a mean streak

The Gunners are often chastised for lacking resilience but they were combative and strong in the tackle from the outset.

Manchester City clearly felt Arsenal went too far on occasion – David Silva vented his anger at referee Craig Pawson over a tackle from Gabriel which forced him out of the game after 23 minutes – but it was refreshing to see a team whose character has been called into question dig in as they did here.

This display was a world away from the capitulations at West Brom and Crystal Palace among others and one which should embolden Arsenal for the dual task of winning the Final against Chelsea and securing a top four finish in the Premier League.

Sanchez delivers on the big stage

Sanchez’s winning goal won’t rank as one of the finest he has ever scored but it settled a pulsating semi-final in Arsenal’s favour to ease the pressure on his manager and team-mates.

He reacted with typical sharpness in the box to turn the ball home from close range just before the midway point in extra-time to send the Gunners into their 20th FA Cup Final.

Sanchez’s performances have dipped in recent weeks, fuelling speculation he could depart this summer given a year left on his existing contract.

However, he has been offered a new contract worth £300,000-a-week to stay at Emirates Stadium and it is precisely for match-defining contributions such as this.

Monreal thrives in wing-back role

In theory, Kieran Gibbs looks more naturally suited to the position but Monreal has made a hugely promising start on the left of Arsenal’s new-look shape.

In fact, the benefits of Wenger’s tactical switch were perfectly encapsulated by his team’s 72nd-minute equaliser as one wing-back, Alex Oxlade-Chamberlain, crossed superbly for the other as Monreal capped a fine individual display with his first goal since scoring in the FA Cup quarter-final at Manchester United in March 2015.