Antony Evans's brilliant free-kick kept Everton's perfect Premier League Cup record as they beat Sheffield United 1-0 at Stocksbridge Park.
The 21-year-old struck on 26 minutes as Everton made it three wins from three in Group B.
The Blues were also indebted to goalkeeper Joao Virginia, who tipped Harry Boyes's shot on to the crossbar in added time.
A first defeat leaves United second. The top two teams progress to the knockout stages.
Jordan Cox scored the only goal as Aston Villa also made it three wins out of three in Group F, beating Plymouth Argyle 1-0.
Four second-half goals earned Derby County their first Group F victory, overcoming Bristol City 4-1.
See: Derby report
Dan Agyei struck late for Burnley as they held West Bromwich Albion to a 2-2 draw in Group C.
Elias Sorensen's 17th goal of the season helped Newcastle United defeat Leeds United 2-0 to go level with leaders Southampton on seven points in Group H.
Goals from Kees de Boer and George Byers secured Swansea City's first win in Group B, a 2-1 success against Hull City at Landore.
See: Swansea report
Jordan Lawrence-Gabriel's close-range goal gave Nottingham Forest a third straight victory in Group D, edging out Norwich City 1-0.