Stand-in captain Juan Mata stepped up with a wonderful free-kick seven minutes from time as Manchester United saw off Watford 1-0 at Old Trafford.
Louis van Gaal handed the Spaniard the armband in the absence of the injured Wayne Rooney, but United were fortunate to be level at the break.
After their morale-boosting 3-2 win over Arsenal at the weekend, earned by a brace from 18-year-old Marcus Rashford, Van Gaal's injury-hit side were given a series of let-offs by Watford striker Odion Ighalo, who missed a host of chances.
United partnered the fit-again Anthony Martial with Rashford and, after the interval, asked questions of Watford before Mata stepped up from 20 yards with 83 minutes on the clock to settle the contest.
With a sixth goalless draw of their Premier League campaign on the cards, Mata found the top corner to move United level on points with fourth-placed Manchester City, who were beaten 3-0 at Liverpool but still have a game in hand on their neighbours.
Watford - who will rue Ighalo's wastefulness and the lack of a second-half penalty for a foul on Sebastian Prodl by Matteo Darmian - can count themselves unfortunate as they failed to edge closer to Quique Sanchez Flores' 40-point target.
While Rashford kept his place up front alongside Martial, Timothy Fosu-Mensah was handed a first start for United as he came in for the rested Michael Carrick.
Watford made four changes from their goalless draw with Bournemouth, and skipper Troy Deeney bullied Fosu-Mensah off the ball early on, allowing Ighalo to send Watford's first effort wide, with the Nigerian then shooting tamely at David de Gea after Daley Blind gave the ball away.
Morgan Schneiderlin volleyed wide at the other end but the chances continued to come and go for Ighalo, who dragged an effort wide before electing to shoot at De Gea instead of supplying Deeney a tap-in.
De Gea denied the luckless Ighalo once more before half-time, following a sloppy backpass from Fosu-Mensah, and the theme continued after the break.
Another poor United backpass allowed Ighalo another sight on goal only to be crowded out with Etienne Capoue almost beating De Gea from distance soon after.
Rashford blocked Prodl's header on the line before United got in the ascendancy as Mata tested Heurelho Gomes before angling a sidefooted effort wide of the Brazilian's goal.
United, often accused of lacking ideas going forward this term, were vibrant up front late on but saw Nordin Amrabat almost benefit when Blind's clearance deflected into his path before Darmian took a risk by hauling down Prodl at a corner.
But United were given their opportunity when Martial was fouled by Miguel Britos on the edge of the area, allowing Mata to provide a captain's contribution and earn a third-straight league win.
Key Opta stats:
- Manchester United named their fourth youngest starting XI in Premier League history (23 years, 222 days old on average).
- Timothy Fosu-Mensah became the third youngest player to make his first Premier League start for Manchester United (18y 60d old).
- Odion Ighalo has scored just one goal in nine Premier League appearances so far in 2016, despite attempting 27 shots (inc. blocked).
- Watford have failed to score in six of their last eight Premier League matches.
