Nemanja Matic hailed the character of Manchester United team-mate Alexis Sanchez after he scored on his return to Arsenal in the FA Cup on Friday night.

Sanchez opened the scoring against his former club as United won their eighth game in a row under interim manager Ole Gunnar Solskjaer to maintain his winning start.

Jesse Lingard added a second with Pierre-Emerick Aubameyang reducing the arrears, only for substitute Anthony Martial to wrap up a comfortable 3-1 victory and secure United's place in round five.

Sanchez has struggled since leaving Arsenal for Old Trafford a year ago and his well-taken goal was just his fifth for the Red Devils.

Solskjaer believes it can be the springboard the Chile international needs to kick-start his career and Matic, too, insists Sanchez's work ethic means he will come good again.

"Alexis has great character," Matic said after the win.

"He works every training session at 100 per cent and I'm happy for him because when you work like that, in the game, you can't play bad so he is doing very well. He helps the team and today, he scored.

"He is a great guy. I'm happy for him because he must understand he is a very important player for us."

While the likes of Marcus Rashford and Paul Pogba have been lauded for their improvements since Solskjaer replaced Jose Mourinho last month, there are other players within the United squad also showing signs of progression.

Centre-back Victor Lindelof enjoyed another fine evening and Matic believes he and midfield partner Ander Herrera know their roles.

"I know my job. All my career, I know my job," he said.

"I know what I have to do and I have to do my best for the team, especially in my position, Ander's position. Sometimes you don't see us on the pitch, but we do important jobs.

"For us, it's more or less the same and we are trying to help the team and the guys in front of us need to express themselves with their talent, the quality, and also to help us defend. I think as a team we work very good."

Asked about Pogba's recent form and his ability to express himself in the team, Matic added: "I think Paul has the ability to do everything.

"A box-to-box player, he helps us in the defence, he also is creative with the ball and that's why he is one of the best players in that position in the world.

Arsenal goalkeeper Petr Cech was making his first start since announcing he will retire at the end of the season.

The 36-year-old will not add to his five FA Cup winners' medals but felt the difference between the two sides was minimal – with United more clinical in front of goal.

"They took their chances and we didn't," he told arsenal.com.

"That was the difference in the game. We are disappointed with that because we wanted to win again after a big win against Chelsea. It wasn't to be.

"We played much better than the result shows. Obviously they created some counter-attacking situations and they punished us from that.

"You can see they are full of confidence, and that's why when they arrive in the last third, they choose the right options to finish their actions.