Ange Postecoglou protégé Riley McGree heaped the relegation pressure on his old team Birmingham City.

McGree, 25, thought it was a prank when he was given his first Socceroos call-up at 17 by the Tottenham Hotspur manager.

But in thundering in a spectacular goal he made it anything but a laughing matter for City.

The result heaps pressure on Birmingham, who have now gone five games without a win.

Riley McGree scored a stunning first-half winner to sink Birmingham City at St Andrew’s

Middlesbrough’s victory pushes them just five points behind the play-off places

Birmingham are one point clear of the relegation zone and haven’t won since manager Tony Mowbray underwent medical treatment – with Mark Venus (pictured) filling in for him 

City haven’t won since manager Tony Mowbray – a Middlesbrough legend – has undergone medical treatment and is currently away from his daily duties.

Both sets of fans chanted his name in the early stages, but it was Birmingham who looked far more in need of the 60-year-old’s guidance.

Birmingham had the first chance when Alex Pritchard attempted a 40-yard chip over goalkeeper Seny Dieng but his ambitious effort drifted wide.

Paddy McNair fired over a long-range rising effort for Middlesbrough after Emmanuel Latte Lath was denied from point-blank range by goalkeeper John Ruddy.

But a mistake by Pritchard led to ’Boro taking a 17th-minute lead.

The former Brentford and Sunderland midfielder’s pass was easily cut out by Luke Ayling.

He teed up McGree to rifle an unstoppable left-foot drive into the top corner of the net from 25 yards.

McGree, who spent 15 months on loan at St. Andrew’s at Knighthead Park from October 2020 to the end of 2021, refused to celebrate his stunning strike against his old club.

Middlesbrough held on to take a narrow win against an unconvincing Birmingham side 

Ayling tried to make it 2-0 after cutting inside and curling goalwards but his attempt was straight at Ruddy.

Pritchard sliced horribly wide on the angle as neither he nor Koji Miyoshi seemed to want to take responsibility to shoot.

If Birmingham’s struggles weren’t summed up by that lack of confidence, they were underlined when no one challenged Latte Lath from Lukas Engel’s throw-in and the striker fired just wide.

Birmingham replaced the out-of-sorts Miyoshi with Juninho Bacuna at half-time.

But they continued to look unconvincing.

There was a four-minute stoppage before the hour mark after referee Andy Davies went off injured, with fourth official Jeremy Simpson taking over the whistle.

The lively Latte Lath only just failed to get enough contact on an up-and-under, with the sliced effort flying over.

Substitute George Hall had the chance to give City a late lifeline but he screwed his shot horribly wide.