In a crazy ending to the first half, Anthony Gordon's penalty put Newcastle in front shortly after Jacob Ramsey had been dismissed, and Casemiro levelled with virtually the last kick before the break.

The second half was far shorter on incident but that owed much to the way Eddie Howe's players dug in to limit opportunities for the in-form visitors - and the performance of Aaron Ramsdale on the occasions when they did break through.

But then Osula raced down the right, cut inside and bent the ball into the Gallowgate net to give boyhood Magpie Michael Carrick a first defeat as Manchester United boss.

Ramsdale had replaced Nick Pope in goal while Havey Barnes also came into the starting XI in the other change from Saturday's defeat to Everton. Nick Woltemade missed out through illness.

The Magpies started the match with real purpose and a Kieran Trippier cross-cum shot clipped a post at the Leazes End inside the opening four minutes.

Then a wonderful move from the Magpies ended in Casemiro blocking a shot from Harvey Barnes.

In the 13th minute, Anthony Elanga - who started his professional career with Manchester United - volleyed narrowly wide. And after Joelinton dispossessed Kobbie Mainoo in his own box, Barnes curled an effort just off target a minute later.

Sandro Tonali was next to threaten, sending a low drive just the wrong side of goal in the 20th minute.

The likes of Tonali, Joelinton and Jacob Ramsey were routinely winning the ball from red shirts - albeit they were sometimes guilty of surrendering possession rather cheaply too - and another swift Newcastle break, from Anthony Elanga to Gordon to the galloping Joelinton, resulted in the Brazilian advancing dangerously but firing over the top.

Shortly before the break, Elanga got to the byline and cut the ball back for Barnes, who attempted to flick beyond Senne Lammens but the Belgian goalkeeper was able to gather.

At the other end, Aaron Ramsdale's first save of the night was a brilliant one as he flew across his goal but push away an arcing shot from Mainoo, with the ball seemingly destined for the top corner of the Gallowgate End net.

Then Ramsdale pushed away a stinger from Matheus Cunha, who had got the wrong side of Kieran Trippier. Bryan Mbeumo blazed over from the rebound.

But in first-half stoppage time, Ramsey was shown a second yellow card for what, in referee Peter Bankes' view, was simulation as he tried to round Lammens. He'd earlier been booked for a tug on Casemiro.

Newcastle, though, kept pushing and Gordon had his heels clipped by Bruno Fernandes in the box. This time, Bankes pointed to the spot - and Gordon converted coolly.

Casemiro, however, headed a Fernandes free-kick beyond Ramsdale deep into stoppage time to restore parity.

Despite their numerical disadvantage, it was Newcastle, through Gordon, who had the first opening of the second period but the England man's shot was easily dealt with by Lammens.

Then Gordon somehow ghosted in unmarked to meet a left-wing Tonali corner, but couldn't quite wrap his foot around the ball at full stretch.

In the 75th minute, Ramsdale made another superb save, showing fine reactions to parry Leny Yoro's downward header.

Fernandes has made that one with an inventive pass and played another one soon afterwards to create another opportunity for his team, but Manuel Ugarte's header dropped over the bar.

Fernandes curled wide in the 82nd minute then Joshua Zirkzee was denied by Ramsdale.

And in the final minute of normal time, Osula - who had been on the pitch less than five minutes - showed pace to race onto Trippier's ball down the line and poise to caress a shot beyond Lammens, sparking scenes of jubilation in the stands and the Newcastle dugout.

Newcastle United: Aaron Ramsdale, Kieran Trippier (c), Lewis Hall, Joelinton, Sandro Tonali (Sven Botman 90+7), Anthony Gordon (William Osula 85), Harvey Barnes (Joe Willock 46), Malick Thiaw, Anthony Elanga (Jacob Murphy 85), Dan Burn, Jacob Ramsey

Subs not used: Nick Pope, Yoane Wissa, Alex Murphy, Leo Shahar, Sean Neave