Middlesbrough 2 Peterborough 0

Boro were awarded a late penalty after McNair was hauled down by Nathan Thompson in the area, and the defender made no mistake as he stepped up to score from the spot.

Peterborough thought they should have had a penalty of their own at the start of the second half, but while Joe Lumley made contact with Siriki Dembele as he slid in to try to win the ball, referee John Busby waved away the visitors’ appeals. In a game of very few chances, it proved a crucial decision.

McNair’s penalty was followed by a second goal from Josh Coburn in stoppage time, with the substitute slotting home after a neat one-two with Martin Payero.

Boro’s defensive crisis meant Neil Warnock was forced to field a makeshift defence, with Anfernee Dijksteel, Dael Fry, Grant Hall and Marc Bola all unavailable because of injury and Lee Peltier serving a suspension.

With arguably his five best defenders out, Warnock opted to field McNair and Jonny Howson as emergency centre-halves alongside Sol Bamba in a back three, with Marcus Tavernier and Onel Hernandez lining up as wing-backs.

The Teessiders’ defence stood firm throughout a turgid first half that saw both sides repeatedly cede possession and struggle to muster any kind of attacking cohesion.

Payero shot over in the early stages after Tavernier pulled the ball into his path and Hernandez saw a lot shot deflected wide, but it was the 42nd minute before Boro mustered an effort on target that actually forced Peterborough goalkeeper David Cornell to making a save.

Tavernier cut in from the right-hand side, but his low strike was too close to Cornell, who was able to make a routine stop.

Boro’s best chance before the interval came in stoppage time right at the end of the half, but while Hernandez fired a decent effort goalwards after cutting inside his marker on the right of the box, Posh defender Joshua Knight did well to block the wing-back’s strike on the goalline.

Peterborough’s only opportunity of note before the break came to nothing when Jorge Grant nodded Samuel Szmodics’ cross over the bar, with Bamba once again performing impressively at the heart of the Boro backline.

The second half began with Sporar directing a diving header wide after good work down the left from his strike partner Uche Ikpeazu, but there was a let off for Boro in the 49th minute.

Lumley caught Dembele as he slid in close to the edge of the penalty area, and while the Peterborough forward was unquestionably looking for the contact, it came, forcing the forward to hit the turf. It looked like a penalty, but referee John Busby waved away the visitors’ appeals.

With the standard of play remaining depressingly low, Ikpeazu headed Matt Crooks’ cross over the bar midway through the second half, before Hernandez received Payero’s through ball in the area, only for his low shot to be saved by Cornell.

The game looked to be drifting to a goalless draw, but Boro made the breakthrough from the penalty spot with five minutes remaining.

McNair was hauled down by Nathan Thompson as he tried to reach Tavernier’s corner, and after dusting himself down, the Northern Irishman hammered home from the spot.

Boro added a second in stoppage time, with Coburn, who was an 83rd-minute replacement for Sporar, sliding a low shot into the corner after a neat one-two with Payero.