Manchester United withstood late pressure from West Brom to seal a 2-1 victory after first-half goals from Romelu Lukaku and Jesse Lingard.
Lukaku's superb header against his former employers sent United on their way (27) before a deflected Lingard strike (35) put them in control before half-time.
Gareth Barry tapped in West Brom's first goal in more than six hours of football (77) to ensure a frantic finish at the Hawthorns, but United clung on for a sixth league win in seven games.
United ultimately close the gap on leaders Manchester City back to 11 points, while Alan Pardew's search for a first victory as West Brom boss goes on, with the club now winless in 16 Premier League games.
West Brom: Foster (6), Nyom (7), Evans (7), Hegazi (6), Gibbs (6), Yacob (6), Livermore (6), Krychowiak (5), Burke (6), McClean (5), Rondon (5)
Subs: Barry (7), Rodriguez (6), Brunt (6)
Man Utd: De Gea (6), Valencia (6), Jones (7), Smalling (7), Young (6), Herrera (6), Matic (7), Mata (6), Lingard (7), Rashford (6), Lukaku (7)
Subs: Rojo (6), Martial (n/a), McTominay (n/a)
Man of the match: Nemanja Matic
After a slow start, United took the lead with the first attempt on target as Lukaku found the top corner with a brilliant glancing header from Marcus Rashford's cross, though it was met with muted celebrations once more from the Belgian after his second goal in as many games.
It got better for United eight minutes later courtesy of Lingard's seventh goal of the season after his effort deflected off Ahmed Hegazi and beyond Ben Foster, who had looked set to make a routine save.
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The home side improved after the break and substitute Barry forced David de Gea to make a comfortable save before Marcus Rashford's first-time strike whistled past the far post down the other end.
One West Brom change saw Oliver Burke make his first Premier League start, with Hal Robson-Kanu dropping to the bench. For United, Ashley Young, Ander Herrera and Marcus Rashford were all recalled to the starting XI.
Lingard almost had his second just before the hour-mark, but the 25-year-old shot straight at Foster after a swift counter-attack from the visitors.
And as United started to sit back, West Brom handed themselves a lifeline in the 77th minute, with Barry poking home the first goal of the Pardew era after a scrappy passage of play from a corner.
West Brom continued to push for an equaliser, but Jay Rodriguez could only head wide before De Gea eventually gathered the ball after another corner caused mayhem in the United defence.
- Manchester United have won their last three away Premier League games, one more than they managed in their previous 10 on the road (2).
- West Brom are now winless in 16 consecutive league games - the longest run in their entire league history (D8 L8).
- Romelu Lukaku has been involved in eight goals in his last eight Premier League games against former club West Brom (five goals, three assists).
- Lukaku has scored 10 goals in his last 11 Premier League appearances at the Hawthorns, a run which spans games with West Brom, Everton and Man Utd.
Man of the match - Nemanja Matic
Matic was United's standout performer in an otherwise uninspiring display from the visitors. The Serbian made vital interceptions to prevent West Brom, while he also carried the ball forward with intent on numerous occasions.
His ability to break beyond West Brom's midfield paid dividends for both of United's goals, while 105 touches in total - 32 more than any other player on the pitch (Ander Herrera, 73) - highlighted how integral he was to United's hard-fought victory.
Alan Pardew: "In hindsight, the team I picked was not the right team. I should have put some fresh legs in there.
"They did so well at Liverpool, and as a new manager I wanted to show some faith in those players, but I should have maybe made two or three changes.
"We looked leggy, we looked not up to the ball. But in the second half we were a lot better and had a lot more conviction to our play - that was the problem."
Jose Mourinho: [On Lukaku celebration] "I didn't celebrate too. Nobody was happier than me, it's just a question of profile.
"I am happy, I'm happy with the victory. But 15 years ago I look at myself celebrating goals and now I feel a little ashamed with that, but with maturity you go into levels where you control your emotions better. Unless, I repeat, you score a winning goal in the last stage of a game.
"Also, I think Romelu had the fact that he was a happy kid at West Brom. He was a kid that was given all the conditions here to have the evolution he had. So probably in the back of his mind is that love for the club."
The pundit - Graeme Souness
"That was a real, hard slog for United. If you're a United supporter, you expect them to be better than that against a team that are huffing and puffing. They made hard work of it, it wasn't a great watch by any means."
West Brom travel to fellow strugglers Stoke on Saturday in a 3pm kick-off, while United are in Carabao Cup quarter-final action at Bristol City on Wednesday - live on Sky Sports Football - before heading to Leicester on Saturday evening, live on Sky Sports Premier League.