Arsenal 1-3 Manchester United in FA Cup fourth round

Alexis Sanchez made a goalscoring return to Arsenal to set Manchester United on their way to a fourth-round FA Cup win which makes it eight straight wins for interim manager Ole Gunnar Solskjaer.

Sanchez has struggled to produce his best form since swapping Emirates Stadium for Old Trafford a year ago but was at his sharpest to take Romelu Lukaku's superb reverse pass in his stride and round Petr Cech to give United a 31st-minute lead.

Lukaku was the creator again two minutes later as Jesse Lingard's precise finish doubled United's advantage - and even though Pierre-Emerick Aubameyang pulled one back before the interval, Solskjaer's side were always in control.

United keeper Sergio Romero's superb save from Aaron Ramsey at the start of the second half was crucial in keeping Arsenal at bay and United were rarely troubled afterwards.

Arsenal's cause was not helped by injuries to key defenders Sokratis Papastathopoulos and Laurent Koscielny; substitute Anthony Martial wrapping up United's latest success when he pounced after Petr Cech could only palm out Paul Pogba's shot with eight minutes of normal time left.

• Lukaku tops your player ratings

• 'Man Utd's stars like different players under Solksjaer'

• Relive the action and follow reaction here

• How to follow the rest of the FA Cup fourth round

Sanchez shows form at last

Sanchez moved from Arsenal to Manchester United with great fanfare, but the 30-year-old's time at Old Trafford has largely been a miserable tale of injuries and lack of form.

The Chilean made his return to the stadium where he was once idolised having scored only four goals from 32 appearances, but here he gave Arsenal's fans a painful reminder of his quality.

He was sharp and mobile - playing on the left of United's attacking trio with Lingard in the centre and Lukaku posted to a profitable role on the right - and deserved his well-taken goal.

Sanchez ignored the inevitable jeers to take his chance with calm and contribute to United's attacking threat with real thrust and energy.

With the in-form Martial and Marcus Rashford starting on the bench, Solskjaer will hope this is a sign of things to come from Sanchez as his United renaissance continues.

Night of pain for Arsenal

This disappointing defeat came at a heavy cost for Arsenal and manager Unai Emery - the exit from a competition in which he had high hopes of making progress compounded by further injuries that will drain his defensive resources.

After losing Hector Bellerin for nine months to a knee injury sustained in the win against Chelsea, Emery is now waiting on injury bulletins for Sokratis, who limped off early on with an ankle problem after falling awkwardly, and Koscielny, whose facial injury resulted in 10 minutes of added time.

Emery's side must now focus on finishing in the top four and progressing in the Europa League; very much the Spaniard's speciality after winning the competition in three successive years at Sevilla.

Arsenal never recovered from that quick one-two between Lukaku and Sanchez just after the half hour. It was always going to be a season of transition after the Arsene Wenger era and this was a hefty bump in the road on Emery's journey.

Man of the match - Romelu Lukaku

BBC One pundit Jermaine Jenas said: "Those assists in the first half helped shift the momentum Manchester United's way. I was impressed by his application and attitude on the right-hand side."

Match stats - a goal every day of the week for Aubameyang

• United have won six matches at the Emirates - more than any other visiting side has managed since Arsenal moved there at the start of the 2006-07 campaign.

• Since losing 2-1 to Arsenal in the quarter-final in March 2015, Manchester United have won more FA Cup matches than any other team (16).

• Manchester United have registered eight consecutive wins in all competitions for the first time since January 2017.

• Since the start of the 2014-15 season, Alexis Sanchez has scored 41 goals in all competitions at the Emirates Stadium (40 for Arsenal, one for Man Utd) - 14 more than any other player.

• Just 149 seconds separated Manchester United's first and second goals - they scored with their first two efforts on target.

• Pierre-Emerick Aubameyang has scored on his Arsenal debut in the Premier League (v Everton), Europa League (v Vorskla Poltava) and FA Cup (v Man Utd).

• Manchester United striker Romelu Lukaku has scored 13 goals and assisted four in his last 15 FA Cup appearances.

• Pierre-Emerick Aubameyang has scored on all seven days of the week this season for Arsenal.

• Jesse Lingard has scored four goals for Manchester United against Arsenal in all competitions - double the number he has scored against any other opponent for the Red Devils.

What's next?

Both sides are back in Premier League action on Tuesday. Arsenal host Cardiff at 19:45 GMT, with United at home to Burnley 15 minutes later.