After Premier League sides Newcastle, Nottingham Forest and Bournemouth were humiliated by lower-league opposition on Saturday, Unai Emery’s Villa were rocked by Stevenage’s two-goal blast in the final minutes.
Premier League champions City rarely suffer such humiliation and they made the strongest possible start by dismissing Chelsea with contemptuous ease at the Etihad Stadium.
Pep Guardiola made seven changes from the City side that won 1-0 at Chelsea in the Premier League on Thursday.
But City were still far too dynamic for struggling Chelsea as Mahrez struck with a brilliant free-kick and a late penalty, with Julian Alvarez and Phil Foden also scoring.
In the fourth round, City will host Premier League leaders Arsenal or third- tier Oxford, who meet on Monday.
City had already eliminated Chelsea from the League Cup this season and the west London club’s first FA Cup third-round exit since 1998 was another blow to a season in danger of spiralling out of control.
While it is probably too early for Chelsea boss Graham Potter to be fearing the sack, just four months after he arrived from Brighton to replace the axed Thomas Tuchel, the 47-year-old might be having a few sleepless nights as he wrestles with his team’s woeful form.
Chelsea have won just three of their last 12 games in all competitions and sit 10th in the Premier League, 10 points adrift of the top four place the club’s American owners would surely have expected Potter to deliver.
Potter will hardly have been comforted by the sound of Chelsea fans chanting Tuchel’s name as they pine for the German who led them to Champions league glory in 2021.
Given Chelsea’s predicament it was curious that Potter elected to make six changes, with Bashir Humphreys given his debut and fellow teenager Lewis Hall also starting.
Mahrez took advantage of Potter’s selection gamble when he drew a rash foul from Hall in the 23rd minute.
The Algeria winger had scored the winner against Chelsea on Thursday and this time he bent a superb free-kick into the top corner from 25 yards.
City’s second goal was a gift from Chelsea forward Kai Havertz, who punched the ball as he challenged Aymeric Laporte at a corner.
Alvarez slotted the 30th minute penalty past Kepa Arrizabalaga despite the Chelsea keeper’s attempt to distract the Argentine World Cup winner by talking to him before the kick.
Chelsea were being torn apart and Foden hit the third goal in the 38th minute, the England forward finishing off Kyle Walker’s cross after Mahrez’s pass unhinged the ragged visitors.
Beaten in the last three FA Cup finals, Chelsea’s misery was compounded in the 85th minute as Mahrez scored from the spot after Kalidou Koulibaly fouled Foden.
Villa boss Unai Emery made eight changes against Stevenage and the team currently second in League Two made the Spaniard pay for his decision.
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.
Leeds were fortunate to avoid embarrassment after escaping with a dramatic 2-2 draw at second tier Cardiff.
Jesse Marsch’s side were shocked by first-half goals from Jayden Philogene-Bidace and Sheyi Ojo.
Rodrigo got one back in the 65th minute, then missed a penalty after Cardiff’s Joel Bagan was sent off for handling on the line.With just seconds left, Sonny Perkins spared Rodrigo’s blushes as the 18-year-old substitute netted from close-range to force a replay.