It was a clinical attacking display from Gareth Taylor’s youngsters, with the in-form Keke Simmonds and Nabil Touaizi also on the scoresheet.
Nmecha, who has a goal and an assist in his last two games at his level, was the star of the show and he got the ball rolling when he latched on to Rowan McDonald’s pass to give City a 17th minute lead.
We extended our advantage 10 minutes before half-time, when Simmonds grabbed his fourth goal in two games.
Full of confidence after his hat-trick in the 6-1 win over Everton, the young striker was felled on a run into the penalty area, but picked himself up to calmly convert from the spot.
The hosts rallied after the break, but City eased to victory with a flurry of goals in the final 10 minutes.
Another composed finish saw Nmecha grab his second of the game, before substitute Touaizi scored a fine effort four minutes from time.
But Nmecha and City weren’t finished.
Rovers again fouled Simmonds in the area and with his hat-trick up for grabs, Nmecha duly dispatched from 12-yards to complete an impressive individual and team performance.
How we lined up
Taylor made four changes to the side that beat Everton, with Tom Scott, Yeboah Amankwah, Fisayo Dele-Bashiru and D’Margio Wright-Phillips all coming into the starting line-up.
Scott was in goal and protected by a back four of Jeremie Frimpong, captain Eric Garcia, Amankwah and Ryan Corrigan.
McDonald screened the defence at the base of midfield, with Dele-Bashiru and Nmecha just ahead of him.
Henri Ogunby, Wright-Phillips and Simmonds formed the front three.
What it means
City remain in fourth place in the U18 Premier League, but are now just one point behind third place Everton and two behind Liverpool in second.
We’ve got a five point cushion over Stoke City below and have a game in hand on all three teams.
Four games remain for Taylor’s youngsters, who make the short trip to leaders Manchester United on Saturday, for a 12pm kick-off at Leigh Sports Village.