Chelsea have one foot in the Youth Cup final after defeating Manchester United at Old Trafford.
Amin Affane gave the visitors the lead inside a quarter of an hour, before James Wilson equalised after the hour.
But Islam Feruz helped The Blues re-take the lead mid-way through the second half giving Asi Viveash’s side the advantage going into the second leg at Stamford Bridge.
Any hopes of United repeating last season’s emphatic victory in the Youth Cup were extinguished after 14 minutes when Feruz and Lucas Piazon combined for the ball to eventually fall to Affane, who swept home.
The home side dominated after the interval, and notched a deserved leveler when Chelsea failed to deal with a corner, with Wilson taking full advantage.
But the holders’ parity existed for just five minutes, when Feruz capitalised on some hesitant United defending to slam home from 25 yards.
Boss Viveash said: “It was obviously a very tight game, and an outstanding advert for youth football.
“The pitch was lovely and our boys thrived on that. We started tremendously well and in the first 20 minutes the game could have been out of sight. We scored a grest goal through Amin Affane and had several other opportunities but unfortunately if you don't take them against Man United, their front three have good movement and in the second part of the first half they worked themselves back into the game.
“In the second half they got the equaliser when we looked liked we were going to get a second but at 1-1, the boys showed tremendous character again to go and get the winner.
“I've told the boys they deserve a big pat on the back for trying to execute a game plan as young players away at Man United and they nearly did it to the letter, but it will be much harder at the Bridge.”
The win continues an excellent week for Chelsea, whose first team reached the Champions League quarterfinal after beating Napoli, while this weekend see Roberto Di Matteo’s side take on Leicester City.
For United, the defeat comes at the end of a week which saw them crash out of Europe for the second time this season, but a weekend reprieve could come in the shape of a Premier League win over Wolverhampton, a three points which could pile the pressure on rivals Manchester City.