Then in the second half it was the exact opposite.
Asmir Begovic then had to be alert to thwart both Martial and Luke Shaw in the space of a minute, before tipping Sanchez's header over, as the game threatened to open up at the Vitality Stadium. The bone of contention remains the focal point of the Manchester United attack, a responsibility which should be bestowed on Marcus Rashford once again, with Romelu Lukaku struggling to perform at his best.
Mourinho knows his side have to pick up a win on Wednesday to stand any chance of finishing top and defeat would leave their qualification hopes hanging in the balance if third-placed Valencia beat Young Boys in Spain.
Jose Mourinho in charge of Manchester United, has never lost a Premier League game to a side managed by an English manager. I said at half-time I was the luckiest manager in the Premier League in a half when the score should be like 6-2. In the first half, Bournemouth were by far the best team and in the second half we were the best team by far. I feel like people watching this game will not believe how hard we trained this week.
Asked how confident he is of Martial staying, Mourinho said: "I don't belong to the discussions of contracts".
But the visitors were vastly improved after the break, with Herrera influential, and fellow substituteMarcus Rashford's scrappy stoppage-time strike stole the three points.
Instead they went in at 1-1, before the customary United improvement in the second half, in which Alexis Sanchez - starting for the first time since September -and Paul Pogba were especially risky.
With Mourinho looking for a centre-back in January, Ake's name has been listed as a potential target.