Smith, Mandron and Mavrias on target at the SoL.
Sunderland U21 3 Tottenham Hotspur U21 0
A dominant first-half display from Sunderland’s U21 side was enough to see them take a crucial three points at the Stadium of Light as their fight for a Barclays U21 Premier League play-off place continues.
A goal from Martin Smith set the young Black Cats on their way before Mikael Mandron and Charis Mavrias struck within a minute of each other to put the hosts three goals ahead at half time.
The second half was a quieter affair but a professional performance from a defence which included U18 full-back Tom Robson, saw the development squad home.
With several first-team players in the ranks, including Jozy Altidore and Ondrej Celustka, Sunderland got off to a quick start and could have scored three goals in the opening ten minutes.
First Mandron came through a challenge with the ball at his feet to find himself running at the last Spurs defender, but fired wide.
Just a minute later a Celustka cross found Mandron unmarked inside the six-yard box, but the striker's attempted flick kicked up off his instep and over the bar.
In the ninth minute Altidore judged a high ball well to turn the Spurs defence before his powerful shot flashed agonisingly past the base of the post.
The hosts continued to pile on the pressure, but Spurs managed to break away with a quarter of the game gone only for Smith’s excellent tackle to save the out-numbered Sunderland defence.
Sunderland’s dominance finally paid off just after the half-hour mark; Smith found himself in space on the edge of the box and played a neat one-two with Mandron before passing the ball into the bottom corner of the Spurs goal from 10 yards.
Spurs rallied with a series of crosses during a 10-minute spell of possession, though the visitors still failed to test Joel Dixon in the Black Cats' goal; Soleymane Coulibaly coming closest when his effort was deflected behind.
Just before the break Sunderland would put the game to bed, finding the net twice in the final minute of the half.
Mavrias burst down the right hand side, beating the full-back before cutting the ball back to Smith who fed into Mandron’s feet, the powerful striker riding a challenge to turn and blast home from 10 yards.
Shortly after the restart a long ball over the top from El Hadji Ba found Mandron, whose exceptional touch allowed him to play the ball into the feet of Mavrias.
The Greek winger cut inside to fire at Tottenham goalkeeper Jordan Archer whose fine save fell back to Mavrias, allowing him to prod into the net.
The second period was a much tighter affair with neither side enjoying a sustained period of pressure throughout.
The visitors' best chance fell to Ruben Lameiras ten minutes after the break; Kenneth McEvoy’s cross was headed down to Lameiras and from the edge of the six-yard box he could only send a fierce shot into the side-netting.
Robson - playing at the Stadium of Light for the first time - produced a fine performance in the second half, under pressure from the pacey McEvoy throughout, though he was guided well by the centre-half pairing of Connor Oliver and Thomas McNamee.
As the game drew to a close Mandron broke down the left-hand side, pulling back to Andrew Cartwright on the edge of the box. His shot was saved spectacularly by Archer before the goalkeeper sprang to his feet to block the follow-up from Mavrias.
Sunderland sit fifth in the Barclays U21 Premier League with the final game of the campaign to come at home to West Ham next week.
Sunderland: Dixon, Celustka, Robson, Ba (Cartwright), Oliver, McNamee, Mavrias, Smith (Agnew), Altidore, Mandron, Honeyman (Watson).
Subs not used: Stryjek, Gooch.