As Riyad Mahrez ignited a 4-0 annihilation in the FA Cup third round on Sunday, Manchester City increased the pressure on Graham Potter, the manager of Chelsea.
Villa was shaken by Stevenage's two-goal flurry in the closing minutes after Premier League teams Newcastle, Nottingham Forest, and Bournemouth were humiliated by lower-league opponents on Saturday.
Premier League champions City rarely experience such humiliation, and they got off to the best possible start at the Etihad Stadium by dispatching despicable Chelsea with ease.
The City team that won 1-0 at Chelsea in the Premier League on Thursday had seven changes under Pep Guardiola.
However, City was still far too explosive for a faltering Chelsea, as Mahrez scored twice—once on a late penalty and once on a fantastic free-kick—and Julian Alvarez and Phil Foden also scored.
City will host either third-tier Oxford or the league's top team, Arsenal, in the fourth round.
Chelsea's first FA Cup third-round loss since 1998 was another setback to a season that was already in danger of getting out of hand after Manchester City ousted them from the League Cup this year.
Although it is probably too soon for Potter to be worried about losing his job, the 47-year-old may be experiencing some insomnia as he struggles with his team's appalling performance just four months after moving from Brighton to take Thomas Tuchel's position.
Only three of Chelsea's last 12 games have been victories in all competitions, and the team is currently 10th in the Premier League, 10 points off of the top-four spot that the club's American owners would have undoubtedly expected Potter to secure.
The sound of Chelsea supporters screaming Tuchel's name as they long for the German who guided them to Champions League victory in 2021 will scarcely have relieved Potter.
Given Chelsea's position, it was puzzling that Potter decided to make six substitutions, starting both Lewis Hall and Bashir Humphreys, a fellow adolescent who made his debut.
When Mahrez drew a careless foul from Hall in the 23rd minute, he profited from Potter's selection risk.
The Algerian winger, who had scored the game-winning goal against Chelsea on Thursday, this time bent a beautiful free kick from 25 yards into the top corner.
Kai Havertz, a forward for Chelsea, gave City's second goal a gift when he hit the ball during a corner challenge with Aymeric Laporte.
Kepa Arrizabalaga attempted to talk to Argentine World Cup winner Alvarez before the penalty kick in an effort to divert him, but Alvarez converted the shot in the 30th minute.
As Chelsea was being destroyed, Foden scored the third goal in the 38th minute by converting Kyle Walker's cross after Mahrez had thrown the beaten visitors off their game.
In the 85th minute, Mahrez scored from the penalty spot after Kalidou Koulibaly fouled Foden, adding insult to injury for Chelsea, which had lost the previous three FA Cup finals.
Aston Villa stunned
Aston Villa had eight changes against Stevenage and the team currently second in League Two took full advantage.
Morgan Sanson put Villa ahead in the 33rd minute but Jamie Reid equalised with an 88th-minute penalty after Leander Dendoncker was sent off for fouling Dean Campbell.
And Campbell sparked wild Stevenage celebrations in the 90th minute when he smashed home from a short corner.
“It is really special. The chairman just said to me it’s the greatest day in his life and he’s been with the club for over 20 years,” said Stevenage boss Steve Evans, whose side face Championship team Stoke in the fourth round.
Villa boss Unai Emery added: “I’m really sorry for the supporters. Today was really so disappointing.”
Leeds escaped with a dramatic 2-2 draw at Cardiff thanks to teenager Sonny Perkins’ stoppage-time equaliser after the second-tier side raced into a two-goal lead.