Manchester United suffered their third defeat in a week as late goals from Juan Zuniga and Troy Deeney gave Watford a deserved Premier League win on Sunday.
The hosts led when Etienne Capoue converted Daryl Janmaat’s cut-back, only for Marcus Rashford to level from close range.
Zuniga powered in with seven minutes to go, 53 seconds after coming on, before Deeney then scored a penalty kick in injury time after Marouane Fellaini fouled Zuniga in the box.
Following a derby defeat by Manchester City last weekend and the midweek Europa League loss to Feyenoord, Mourinho and United have had a rough eight days.
It is the first time Mourinho has lost three consecutive games in a season since February 2002, when he was FC Porto boss.
But the self-proclaimed “Special One”, who has won eight league titles across Europe and the Champions League twice, has now lost 11 of his past 21 Premier League games.
This was when he was in charge of Chelsea and Manchester United.
Mourinho made five changes to his starting line-up from the trip to the Netherlands, with Wayne Rooney and Zlatan Ibrahimovic restored to the side.
But United were still disorganised and ineffective, particularly in the first half.
The United boss looked unhappy with the home side’s opening goal, feeling Anthony Martial was fouled by Miguel Britos.
But he will surely need to look more closely at his own side’s failings as they drifted six points behind league leaders Manchester City.
Rooney, Ibrahimovic and the 89 million pounds Paul Pogba all struggled to make an impact on the game.
At the back also, United failed to cope with Watford’s energetic pressing and the crosses from wing-backs Janmaat and Jose Holebas.
Pogba, who returned to Old Trafford from Juventus in the summer, continued to look far from being the most expensive player in the world.
Even though he was deployed in a deep midfield role alongside Fellaini, it still did little to get the best out of the France international.
He did have United’s best effort in the first half, hitting a 25-yard dipping shot that struck the crossbar.
But his attacking talents were wasted so far away from the opposition’s goal and, after starting the past five games, Mourinho will have to consider dropping Pogba.
The alternative will be changing his system to accommodate the 23-year-old.
While most of Mourinho’s side toiled, the rise of Rashford continued.
The 18-year-old England striker scored on his first Premier League start of the season, taking his tally to 10 in 23 games.
He even started the move for his goal, playing a one-two with Ibrahimovic, whose cross dropped to Rashford’s feet for an easy finish from five yards out.
Hornets boss Walter Mazzarri, who managed Zuniga at Napoli, leapt for joy when the midfielder applied the finish to Roberto Pereya’s cut-back with his first touch.
Mazzarri had numerous run-ins with Mourinho during their time in Italy — with the former Inter manager saying the Italian was a hard-working “donkey” that would “never become a thoroughbred”.
Mazzarri, who took over at Vicarage Road in the summer, insisted before the game that he and the Portuguese get on fine now.
But he could not hide his delight when his side went 2-1 up and danced on the side of the pitch.
With numerous chances in the first half, Mazzarri’s men should have been further ahead at the break.
This included an open goal for Odion Ighalo after goal keeper David de Gea dropped the ball.
But they scored a thoroughly deserved opener when Martial was dispossessed and Janmaat teed up Capoue.
Watford looked like their pressing game had taken the energy out of their performance as United improved in the second half.
But they responded late on for their second win of the season and first at home.
