Kevin Cooper's men defeated at New DenCardiff City's Under-21s will have to wait to secure a top two spot in the PDL2 South table following a 2-1 defeat to Millwall at the New Den.
Josh Wright gave the Lions an early lead as he headed home a Jack Powell corner in the tenth minute of play, a lead the Lions held on to until the break.
Despite plenty of pressure from Cooper's men, it was the hosts who grabbed that all important next goal just after the hour mark as Connor Hunte curled the ball past the helpless Ben Wilson in the City goal.
Tommy O'Sullivan scored in the 90th minute to raise hopes of a Hawthorns style comeback for the young Bluebirds, but it was not to be on this occasion as the Lions claimed all three points and the Bluebirds succumbed to their second consecutive defeat.
FULL REPORT TO FOLLOW....
Teams - Millwall: Bywater; Siafa, De Havilland, Wood, Smith; Powell, Bailey (Farrell 71), Wright; Hunte (Guinchard 74), Philpot, O'Brien (Parr 84). Subs not used: Farrell, Peter.
Cardiff City: Wilson, Coulson, Owen, James, Yorwerth, Amondarain, Wharton (B Watkins 86), Williams (Griffiths 78), Roche, O'Sullivan, Hawkins (Bowen 59). Subs not used: Matthews, Bell.