Reserves: Chelsea 0-1 VILLA
The midfield maestro rose highest to thump home a header from a Zoltan Stieber centre on the hour mark.
The victory helped extend the 100 per cent record - adding to the earlier wins over Stoke, Tottenham and Arsenal.
Villa struggled to get into their stride early on as Chelsea started very brightly.
Kevin MacDonald's men created their first chance on 10, Stieber crossing from the left but Hilario came out to collect.
Sinclair fired marginally over the bar eight minutes later.
Parish did brilliantly to save Sinclair's drive on 25 after Sidwell miskicked in the box.
Three minutes later, Stieber broke down the left and fired in an impressive centre. Williams controlled the ball and his eventual drive was well saved by Hilario.
Stieber saw a 25-yard free-kick whistle tamely past the post on 40.
Villa broke down the left through Stieber again on 43 and his cross was headed back across goal by Collins but the Chelsea rearguard managed to clear.
Tejera saw a 25-yard strike crash against the upright on 45 and in injury time, Collins had an effort from close range fly just wide.
The hosts made a half-time substitution, Mellis coming on for Ferreira.
Williams created a chance of his own on 47 but Hilario made a good save low down to deny the Villa striker.
Clark headed straight at the keeper three minutes later as he got on the end of a Bannan free-kick from the halfway line.
Williams headed just wide on 56 from a Bannan centre.
Stieber, after great interplay, played in a wonderful cross from the left and Sidwell rose to head past Hilario into the bottom corner on 60 to give the claret and blue troops the lead.
Parish did brilliantly to save at the feet of Kakuta on 67 while four minutes later Nouble replaced Tejero.
Magnay was dismissed on 74 for two yellow cards after fouling Williams and kicking the ball away.
Herd saw an effort fly wide on 79 after meeting Stieber's pass inside. Three minutes later Collins's strike went wide too.
Forrester replaced Stieber on 84.
Chelsea: Hilario, Ofori-Twumasi, Bridcutt, Hutchinson BOOKED, Magnay SENT OFF, Taiwo, Ferreira, Tejero, Borini, Kakuta, Sinclair. Subs: Heimann, Mellis BOOKED (for Ferreira, HT), Fernandes, Tabor (for Hutchinson), Nouble (for Tejero, 71).
VILLA: Parish; Lichaj, O'Halloran, Roome BOOKED, Clark BOOKED; Herd BOOKED; Sidwell BOOKED, Bannan, Stieber BOOKED; Collins, Williams. Subs: Baker, Dau, Forrester (for Stieber, 84), Lowry, Grocott.