JOIN USStoke claimed a place in the League Cup quarter-finals with a shock 1-0 win at Aston Villa, while Brentford reached the last eight for the first time with a surprise 3-0 victory against Fulham on Thursday.
Villa have won their first two Premier League games this season, but boss Dean Smith made 11 changes for Stoke's fourth round visit and his understudies were not up to the task.
Stoke also fielded an under-strength team, but Michael O'Neill's Championship team won it in the 26th minute when Sam Vokes headed in Jordan Thompson's corner.
It was their second top-flight scalp this season after beating Wolves in the League Cup last month.
After reaching the final last season, when they lost to Manchester City at Wembley, this was a more forgettable exit for Villa.
Brentford earned a measure of revenge for their Championship play-off final defeat to Fulham last season as they swept aside their Premier League opponents.
Facing a struggling Fulham side who made a host of changes, Thomas Frank's team took the lead eight minutes before half-time in their swish new stadium.
Iran midfielder Saman Ghoddos took advantage when Jean Michael Seri lost possession, found space down the right and squared the ball for Finnish youngster Marcus Forss to slam home.
Said Benrahma, linked with several Premier League clubs, doubled the Championship side's lead when the Algerian forward arrived at the far post to finish off Ethan Pinnock's header.
Making his first start of the season, Benrahma finished off west London rivals Fulham with a superb strike from long-range in the 77th minute.
"We are where we are. This is a team in transition, we came fourth in the Championship last year," Fulham boss Scott Parker said.
"The players are learning, it's new to them. When you go up to the Premier League you need to learn quickly.
"But we're not the only team to have lost three matches. There are issues that need to be resolved and hopefully we will do that."
Tottenham, Newcastle, Manchester City, Manchester United and Everton reached the quarter-finals on Tuesday and Wednesday.
Later in Thursday's last 16 action, Liverpool meet Arsenal for the fourth time in 11 weeks.