The latest and most surprising of United's inexplicable losses, the others coming at Coventry and Southampton, was inflicted by Tony Cottee, who was only playing because of the lack of a fit alternative in a Leicester team that had failed to win any of their previous eight games.
So sluggish was United's first-half performance that they deserved their fate, even though they pulverised Leicester in the second half and seemed just a goal away from scoring a bundle.
Ferguson agreed and said: "We had a terrible start and were too casual to win a game of football. The second half was a marked improvement but I think we got what we deserved. We were too lax, dwelling on the ball and were caught in possession so many times.
"Leicester's work ethic earned them the win and my players will be working just as hard for the rest of the season. They can be sure of that."
Too confident by half. United kicked off in that sluggish fashion which can often creep into their play against teams they are expected to brush aside. They conceded possession too easily, allowing Leicester to settle. When Leicester ran at the United defence they were forced into the uncustomary position of having to stand their ground as if they were the away team.
Strange as it sounds, Leicester's opening 28th-minute goal was as inevitable as it was deserved. Garry Parker pumped in a near-post cross from the right, the substitute defender Henning Berg hesitated, the ball bounced over his head and Cottee nipped in behind to beat the stranded Peter Schmeichel with a first-time volley.
Cottee started the season playing in Malaysia, after being released by West Ham, and was recently loaned to Birmingham. He must have been saving up this performance for some time.
United could have been further behind before the interval. Only after the restart did they play with urgency, but it took a while for the quality to show. Ferguson resisted the temptation to bring on Teddy Sheringham at the start of the second half, but his patience snapped 10 minutes later when he withdrew Berg, put David Beckham at right-back and sent on the England striker.
Now the chances flowed but Kasey Keller was inspired in the Leicester goal, saving from point-blank range and in four one-on-one situations. The finishing was woeful too with Andy Cole, Ole Gunnar Solskjaer and Sheringham, in particular, the guilty men.
Sheringham missed from two yards in the final minute and the Leicester manager Martin O'Neill admitted: "I could already see us restarting the game from the centre circle. This result will not alter United's path, but it gives others hope and it was a great day for Leicester City."Reuse content