Ramiro Funes Mori played 74 minutes as Antony Evans' second-half goal secured Everton Under-23s' progression to the knockout phase of the Premier League Cup at Oakwell.
Barnsley fielded no less than six players with first-team experience this season but the Blues thoroughly deserved the spoils after a dominant second-half display.
Mason Holgate played the best part of an hour for Everton while, having managed 45 minutes against Arsenal last week, Funes Mori got another good run-out under his belt as he stepped up his recovery from a serious knee injury.
The hosts enjoyed the better of the exchanges in the first period and Mateusz Hewelt was certainly the busier of the two goalkeepers, the Everton youngster beating away a well-struck drive from Brad Potts and a powerful Jason McCarthy header.
Everton did have their moments in the opening 45 minutes, however.
Evans, who was the captain of the side, did well on the right of the Barnsley penalty area but, when he pulled the ball back for the incoming David Henen, the Frenchman fired over.
Barnsley came close to breaking the deadlock when a Ben Williams centre from the left was headed just over by Christopher Knasmullner.
The Tykes then squandered a golden opportunity to take the lead when Mamadou Thiam completely missed the ball when he swung his foot to shoot, with only Hewelt to beat.
The second-half, though, was virtually all Everton.
Six minutes after the restart, the Toffees should have taken the lead but Barnsley old-boy Holgate missed the target from 10-yards out after the home defence failed to clear a corner.
Soon after, the Blues had an even better chance when Bassala Sambou was fouled inside the box only for the same player to then hit the bar with the resulting penalty-kick.
As Everton turned the screw, Sambou was then denied by Jake Greatorex, who pushed the striker’s header around the post.
Barnsley struggled to get out of their own half in the second period as the visitors took complete control of the game.
And Evans' goal came in the 73rd minute as he picked his spot from 20 yards and finished precisely with a low shot to earn his side the victory.
Everton: Hewelt, Markelo, Gibson, Denny, Holgate (Feeney 60), Funes Mori (Collins 74), Evans (c), Grant (Baxter 62), Hornby, Sambou, Henen.
Unused Subs: Hilton, Lavery.