Boro's Under-23s were leapfrogged by West Brom in the PL2 table after defeat to the Baggies this afternoon.
Graeme Lee's side, who were looking for a return to winning ways, were behind with two minutes gone through Rayhaan Tulloch.
Rumarn Burrell levelled the scores with a few minutes to spare of the first half, but the Baggies restored their lead inside the first minute of the second period courtesy of Chris Willock.
The home side then struck twice in the space of ten minutes to seal the victory, and to climb above Boro in the league standings. Jamie Soule and Dara O'Shea the scorers for the Baggies.
Attentions turn back to the Premier League Cup for the U23s next Monday, with a trip to Crystal Palace (1pm kick-off).