Three second-half goals condemned a young Boro side to defeat at home to Brighton on Friday.
The Seagulls struck three times after a goalless first half to leave Boro still searching for a first PL2 point of the season.
Middlesbrough U21: Connor, Tawiah (Patterson-Powell 68'), Lindo, Traore, Samuels, Myers-Smith, Eric Hamelberg (Greenup 75'), Simpson, Lennon, Coulson (Bakre 68'), Matthews
Subs: Bakre, Patterson-Powell, Wilson, Greenup, Fisher
Brighton and Hove Albion U21: Hall, McConville (Tasker 65'), Penman, Simmonds, Slater, Albarus, Mullins, Bashir (Ifill 65'), Howell (Knight 80'), Duffus (Flower 75'), Moulton
Subs: Knight, Ferdinand, Flower, Tasker, Ifill
It was the visitors who had the better of the chances during an opening period that was hampered by a strong wind.
Nathan Simpson did go close early on for Boro, but Shea Connor was the first of the two keepers to be tested when he saved from Brighton's Harry Howell.
Connor also saved from Joshua Duffus before Remiero Moulton rattled the bar when the visitors threatened again.
Connor was called upon again just two minutes into the second half when he saved from Sahil Bashir.
The Boro keeper was beaten moments later, though, when Duffus rattled home Brighton's first of the afternoon.
Mark Tinkler's side almost responded immediately. Eric Hamelberg sent a shot over the top and Charlie Lennon was denied by the visiting keeper.
The game was a real stop-start affair, littered with free-kicks, and the visitors were always in control.
Howell sent a free-kick over the top and Jamie Mullins fired wide, but Brighton doubled their advantage with 11 minutes left, Louis Fowler converting from close range.
The third goal came in the final minute when Moulton touched home from inside the six-yard box.
Possession
56%Shots
11Shots On Target
7Corners
4Fouls
172
0
Cards
3
0