Zlatan Ibrahimovic's introduction as a second-half substitute proved crucial as Manchester United finally discovered a way to beat newly-promoted Brighton and Hove Albion 1-0 at Old Trafford on Saturday.
The goal came from a 67th-minute corner, conceded by Solomon March but hotly disputed by the visitors, and their anger increased when Marcus Rashford's cross was headed out to Ashley Young whose shot took a cruel deflection off defender Lewis Dunk on its way into the net.
But it had looked like being a frustrating afternoon for Jose Mourinho until his decision to bring on Swedish veteran Ibrahimovic for his third substitute outing in a little over a week following a seven-month injury lay-off.
Brighton had only beaten United once before in their entire history, 35 years ago, but if they were over-awed by the visit to Old Trafford, they certainly did not show it.
Indeed, the best chances of the opening exchanges were carved out by the visitors, sitting proudly in the top 10 of the Premier League table before kick-off.
Just three minutes had gone when Anthony Knockaert worked his way to the byline and sent over a dangerous cross which came tantalisingly close to finding team-mates Glenn Murray and March.
David De Gea was called into action twice in quick succession, making what turned out to be routine saves to gather shots from Pascal Gross and the increasingly busy Knockaert.
Brighton's approach certainly made for an open game with United keen to cut rivals Manchester City's lead at the top of the table to five points.
After two minutes, Romelu Lukaku had played a neat one-two with Anthony Martial, only to undo the good work by leaning back and shooting high over the Brighton goal.
A well-aimed Martial cross from the left almost set up another chance for the Belgian striker but keeper Mathew Ryan rose well to collect and, in their attempts to get Lukaku more involved, Juan Mata's 24th-minute cross picked out his team-mate but he was unable to put any power into his headed effort.
After limiting United's attack so convincingly, Albion were growing in confidence as the half-hour passed and Ryan had still not been tested.
- Lukaku chance -
It took until the 33rd minute for United to force so much as a corner and, a couple of minutes later, when Antonio Valencia crossed promisingly from the right, it was predictable that Lukaku could only head wide inside a crowded six-yard box.
In fact, Brighton again looked the more likely to score when Gross's free-kick was flicked on and Murray flung himself at the ball, narrowly missing contact with what would have been a spectacular diving header.
And when Ryan was finally tested, in the last minute of the first half, he proved equal to the task, making a magnificent double save on his goalline to block a Lukaku header and Paul Pogba's follow-up from a Rashford cross.
Brighton retained a strong foothold in the game after the restart, with Murray coming close to making telling contact on Gross's cross and Davy Propper shooting over from 25 yards.
United responded, with Mata shooting directly at Ryan, Lukakau almost playing in Pogba with a back-heel and Young planting a left-foot shot wide.
But, by the 62nd minute, Mourinho had seen enough and brought on Ibrahimovic, who won a corner with his first touch and instantly raised the atmosphere at Old Trafford with the opening goal coming just four minutes later.
Still, Brighton were undaunted, with Dunk leading a breakaway charge upfield before flicking a weak shot at De Gea and Knockaert sending over yet another dangerous low cross-shot which passed just beyond the far post.
In the closing stages, Shane Duffy almost met a far-post set-piece for Brighton while Ibrahimovic had two shots on goal without managing to test Ryan.