Goals from Charlie Brown and Thierno Ballo were enough to cancel out Alex Gilbert’s early opener.
The Bees started in great form as they struck after just four minutes when Lachlan Brook, who made his first start for the young Bees, threaded the ball inside from the right into the path of an unmarked Fredrik Hammar. The young Swede then picked out the youngster who finished from close range.
Brook would have another attempt just a few minutes later when The Bees broke forward, and after combining well with Max Haygarth, he miscued his effort.
A golden opportunity to make it 2-0 would fall just after 20 minutes when Brook linked up well with Fin Stevens on the right-hand side before another low cross came right along the Chelsea box, but Gilbert was unable to replicate his earlier finish as he sent the ball over.
More chances would follow moving towards the break with the Brentford Trialist seeing his powerful drive well blocked before Brook would shoot over from the rebound.
Going in to the final five or 10 minutes before the break, the home side began to see more of the ball as they forced The Bees to do some of their first real defending of the match. A late chance before half-time would fall for Brown when he latched on to a cross from the Chelsea right, but he was unable to keep his attempt on target as Neil MacFarlane’s side took a deserved lead into the break.
A couple of changes at half-time would see Aubrel Koutsimouka and Paris Maghoma introduced, and it was a tough beginning to the second period when Chelsea were awarded a penalty on 47 minutes. After Brown raced away, he was adjudged to have been pulled back by Kane O’Connor and the referee immediately pointed to the spot.
Brown then stepped up to finish coolly past Ellery Balcombe low into the bottom right-hand corner. That followed Chelsea’s best spell where they began to look lively going forward through the pacey attack. On the counter-attack Chelsea would go ahead just before the hour mark when a clever move with some first-time passing saw Ballo played in one-v-one with Balcombe before the Chelsea youngster finished with composure.
Despite falling behind, The Bees managed to put the setback behind them as they looked to go back level. Haygarth continued to be a threat down the right with Stevens offering support on the overlap with some dangerous crosses.
On 66 minutes Gilbert would have another chance when the Trialist, tenacious in midfield, shrugged off a couple of challenges before threading the ball forward but the youngster was unable to convert as his left footed effort nestled just wide of the post.
Pressley would continue to pose a threat with his physicality up top as he headed goalwards 10 minutes from time following a cross from the right from Gilbert but, once again, the ball would land the wrong side of the post.
Tristan Crama, Hammar and Pressley himself would all have good chances in the dying moments as Neil MacFarlane’s side put their opponents under significant pressure, but they were unable to make it count as they slipped to a 2-1 loss.
Chelsea U23s: Bergstrom, Wakely, McClelland, Ekwah, Nunn, Elliott, Brooking, Drinkwater, Brown, Lewis, BalloSubs: Wiggett, Wady, Fiabema, Humphreys, Tauriainen
Brentford B: Balcombe, Stevens, D. Thompson (Trialist, 80) O'Connor (Crama, 73) Trialist, Haygarth (Gordon, 73) Hammar, Pressley, Gilbert, Brook (Maghoma, 45), Hockenhull (Koutsimouka, 45)Subs not used: Andersson, J. Thompson, Hercules, Carre