RUBEN AMORIM hopes his Manchester United team are finally coming of age after producing an ‘adult’ performance.The Portuguese boss was feeling the heat following a disastrous defeat at Brentford last week.EPARuben Amorim had reason to be positive after the Sunderland win[/caption]GettyBenjamin Sesko scored his first Old Trafford goal[/caption]GettySenne Lammens impressed on his debut[/caption]But this time it was nothing like kids’ stuff from his Red Devils.First-half goals from Mason Mount and new boy Benjamin Sesko capped a more mature performance — while debutant keeper Senne Lammens kept a clean sheet.Amorim said: “It was not the perfect performance — we had our moment. But we were a competitive and adult team.”England ace Mount got the nod ahead of big-money summer buy Matheus Cunha and repaid his manager with his early goal.Afterwards, he insisted the players are very much with Amorim — despite speculation the United boss could lose his job.Mount said: “We’re 100 per cent behind the gaffer. We’ve had some results that hurt us – the team, the staff and the fans.“But that was an important win.”And Amorim said: “I know they want to do the best and I know they don’t want to change the coach all the time. But we need to show with actions.BEST FREE BETS AND BETTING SIGN UP OFFERS“I feel it during the week but we need to show it on the pitch. Sometimes they know we can do better.”After the international break, United travel to Liverpool before hosting Brighton — a bogey team in recent years. And Amorim bemoaned the fact his team cannot seem to secure back-to-back victories.He added: “There is no momentum with the international break or without the break.“We know what happens when we win one game. The frustration is not to see the same team at home and away.”Sesko followed up his opening goal for the club last weekend with his first at the Theatre of Dreams.He said: “It was important to win the game for the general mood.“We showed once again that we can play well and win games. It’s important now to continue like that.”Sunderland never really recovered from the two early goals. They thought they had a penalty on the stroke of half-time following a high boot from Sesko but it was overturned by VAR.Boss Regis Le Bris said: “We are disappointed but we are still a young team with not much experience together so we will see ups and downs.“Obviously we don’t want to be too negative when we lose but it’s a strong reminder because this league is very demanding.”