It was the battle of the academy products at Stamford Bridge on Wednesday night as Frank Lampard's youth revolution took on Ole Gunnar Solskjaer's tribute act to Sir Alex Ferguson.
And it was Manchester United who came out on top, primarily thanks to Marcus Rashford.
The England international has faced some criticism this season. However, he now looks back to something like his best, with Rashford netting both goals as United beat in-form Chelsea 2-1 to progress to the quarter-finals of the Carabao Cup.
The Blues had come into the game having won their seven previous matches in all competitions, but while Lampard named a much-changed line-up, Solskjaer put out a strong team to try to maintain the momentum his side have started to build up since drawing with Premier League leaders Liverpool.
Rashford proved the key selection on the Norwegian's part. It was he who held his nerve to put United ahead from the spot in the 20th minute, after Daniel James was bundled over in the area by a clumsy challenge from Marcos Alonso.
United had missed four of their previous six penalties, with Rashford even squandering one in Sunday's win at Norwich. However, he did not hesitate when presented with another in west London, and converted with aplomb.
Michy Batshuayi levelled matters in sensational fashion, winning a duel on the halfway line with Harry Maguire, running 20 yards before firing home from the edge of the area.
It was a fine strike from a player trying desperately to prove himself at Chelsea, but it was completely overshadowed by the winning goal, with Rashford employing a Cristiano Ronaldo-esque technique to bamboozle Willy Caballero with a sublime free-kick from 30 yards out with just 17 minutes of normal time remaining.
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The 21-year-old has been outshone by Chelsea's Tammy Abraham in the Premier League this season, but this was yet another performance that made a mockery of the criticism he had been receiving in recent weeks.
Chelsea certainly did not need any reminding of Rashford's talent. He has scored more goals against the Blues (five) than any other side.
What is more, he now has seven goals this season, which is a decent return at this stage of the campaign for a player who plays across the forward line for a team that has proven maddeningly inconsistent to date.
Now, though, both Rashford and United seem have rediscovered their confidence.
As for Chelsea, this simply looked like a game too far for a young squad that has been doing a fine job of balancing their top-four push in the Premier League with their attempts to reach the knockout stage of the Champions League.
Lampard rung the changes, bringing in the likes of Marc Guehi and Billy Gilmour, but they still looked a little jaded.
Indeed, Chelsea were bossed in midfield by a dogged United side keen to improve the negative narrative around their club. Scott McTominay was particularly impressive, dominating the engine room in a manner that evoked memories of Paul Pogba's commanding performance when the two sides met in the FA Cup last season.
Of course, Chelsea will still be happier overall with how their season is going and while they will be disappointed with the defeat, the last-16 clash allowed Lampard to blood more youngsters, with a total of four academy products starting in west London, with a further two on the bench.
United had their own young guns on show, of course, and there are obvious parallels between two clubs hoping to use youngsters to help them rebuild and close the gap in the league to Liverpool and Manchester City.
Solskjaer lauded Chelsea's academy ahead of kick-off but, on the night, Rashford reminded everyone that United are still producing quality players themselves.
He has revived their season and restored hope among the fans.
"We’ve been in a tough place," the striker admitted afterwards. "We’re still getting through that phase."
As he showed against Chelsea, Rashford will be key to United's hopes of coming out the other side.