Marcus Rashford came off the bench to score twice as Manchester United beat Charlton 3-0 to reach the League Cup semi-finals on Tuesday, while Newcastle saw off Leicester 2-0.
A youthful United side featured eight changes as Erik ten Hag had one eye on Saturday's derby against Manchester City at Old Trafford.
One of those retained in the starting line-up from Friday's 3-1 win over Everton, Antony, made the breakthrough with a sumptuous strike on 21 minutes.
Charlton were roared on by a travelling support of 9,000 and the third-tier side kept the tie alive despite Ten Hag introducing Casemiro, Rashford and Christian Eriksen off the bench for the final half hour.
Rashford finally made the game safe for the hosts in the 90th minute, scoring for the eighth straight game at Old Trafford.
The England international then took his tally for the season to 15 with a thumping finish from Casemiro's pass deep into stoppage time.
"We had to be in that semi final and we did the job," said Ten Hag.
"I think we had to finish this off early on but in the end the objective was to get through so compliments to the team."
Newcastle are into the semi-finals of the League Cup for the first time since 1976 as Eddie Howe's men moved one step closer to ending a 54-year wait for silverware on Tyneside.
"It would mean everything to win a trophy but we just need to focus on the next game," said Newcastle right-back Kieran Trippier.
"The supporters here are brilliant. They follow us in numbers and it's always a great atmosphere at home. We want to make them proud by giving everything on the pitch."
The Magpies swept Leicester aside in a recent 3-0 win at the King Power in the Premier League and only a lack of ruthlessness from the hosts kept the Foxes in the game for an hour at St. James' Park.
Bruno Guimaraes, Sean Longstaff and Callum Wilson were guilty of passing up big chances before half-time.
Instead, it was the unlikely figure of Dan Burn who opened the scoring. The giant left-back slotted home coolly with his right foot.
Joelinton quickly doubled Newcastle's lead with a calm finish from Miguel Almiron's pass to leave the home fans dreaming of a visit to Wembley next month.
Manchester City remain favourites for the competition they have won four times in the last five years with Pep Guardiola's men in quarter-final action away to Southampton on Wednesday.
Nottingham Forest host Wolves in the other last eight tie.