A first-half penalty from Juan Mata and a slotted finish from Romelu Lukaku saw Manchester United knock Reading out of the Emirates FA Cup on Saturday.

Danny Loader and Callum Harriott both went close for the Royals, with substitute Sone Aluko also testing Sergio Romero between the posts for United.

Despite a spirited performance at Old Trafford, the Royals will rue missed chances in a largely even encounter in Manchester.

Loader, who led the line as Reading's Under-23s played at Old Trafford back in September, was the Royals' main striker as play got underway. Callum Harriott was also involved from the start for the first time in two years, having scored after coming off the bench on New Year's Day at home to Swansea.

The Royals started positively at Old Trafford, keeping the lion's share of possession in the early stages and pressing the hosts into mistakes - with Sergio Romero scuffing clear under duress from the on-rushing Andy Rinomhota.

There was an early injury scare, though, as Tiago Ilori went down awkwardly on his arm under the challenge of Romelu Lukaku. He required lengthy medical attention, but was able to carry on.

United's quality started to show 15 minutes in. They broke forward with Fred feeding Scott McTominay on the right. He touched quickly to Alexis Sanchez - who controlled and struck venomously, narrowly over Anssi Jaakkola's crossbar.

Up the other end, Reading broke quickly with Liam Kelly looping a ball over the top to Garath McCleary. The winger cut inside, played low across goal with Andy Yiadom ready to strike. He couldn't keep his effort on target, though, and it ballooned away for a goal kick.

The first use of VAR in the history of Reading Football Club followed shortly after. A tackle on Juan Mata from Omar Richards in the box saw the referee play advantage. Fred slotted into the bottom corner, but the offside flag was raised. The referee consulted the video officials and, after a minute's deliberation, and a penalty was awarded.

Mata stepped forward to take, sent Jaakkola the wrong way and put the hosts ahead midway through the first half.

United briefly hit their stride after scoring, but the Royals caught them napping when McCleary fed Harriott on the right with United's defence lagging behind. He squared across to Loader, who was through on goal. He rounded Romero, but the angle was too acute to cut back in and the goalkeeper recovered to make a save.

Reading kept up the pressure, a ball from Richards found its way to Harriott on the edge of the box. He had time to touch into a shooting position, and leathered an effort past the upright.

The Royals had the better of play going towards half-time, but had improvise as a close-range backpass saw Jaakkola have to clear quickly after Rinomhota had tracked back to tackle Sanchez near the Reading area.

Romero had to be on his toes with Swift dispossessed Andreas Pereira on the edge of the United box, Harriott capitalised to shoot but the goalkeeper got both hands behind it and gathered.

Reading kept up their push into first-half added time. Swift turned neatly in the box to set Yiadom up for a strike, he put it on target and Romero had to parry behind for a corner.

Despite the late pressure from the Royals, United doubled the lead just before the interval. Sanchez threaded through the defence, playing in Lukaku, who rounded Jaakkola and tapped into the empty net to round off a half in which two chances led to two goals for the hosts.

Half-time | Manchester United 2-0 Reading

Sone Aluko was introduced at the interval for the Royals, in place of Ilori. This pushed Yiadom back into centre-back, while Rinomhota dropped in at right-back.

In another bright start, McCleary was able to make tracks on the left. He cut back for Loader, who squared to Swift 20 yards out. The midfielder put his foot through it but only to sail over the crossbar.

And when Loader was brought down 25 yards from goal under the challenge of Matteo Darmian, Swift bent over the wall and Romero had to watch it all the way to gather.

Rather than falling away, Reading kept up their assault on the United goal in the hope of pulling one back. Aluko bided his time on the edge of the box and picked the right pass to Harriott in the area. He was able to shoot but Romero saved smartly to keep the Royals at bay.

Mo Barrow was introduced on the hour mark for the Royals, while Marouane Fellaini and youngster Tahith Chong, who recently played against Reading's Under-23s, was brought on for the hosts.

England striker, Marcus Rashford was also subbed on for United after Sanchez went off with injury.

United almost had a third when skipper Ashley Young cut inside past two Royals, laid off to Fellaini from close range. The big Belgian couldn't get it out of his feet, though and Jaakkola was able to save.

Reading broke quickly soon after, Harriott dispossessed Young and Mo Barrow advanced at goal. Barrow got past his marker, cut back for Aluko to shoot, with Romero having to be at full stretch to palm around the post.

Yakou Méïté was introduced in place of Harriott as José Gomes added another attacking presence, with 15 minutes to try and force a replay.

A slick move from the Royals resulted in Richards crossing deep for Méïté at the far post. His effort went over the bar, but the flag was up against him for offside regardless.

The hosts seemed content to keep the ball in their own half as they ran down the clock at Old Trafford.

The match saw the Royals enjoy more possession, take more shots and have more efforts on target than their Premier League opposition, but United ended the match with two goals and passage to the Fourth Round of the Emirates FA Cup.

Full-time | Manchester United 2-0 Reading

Manchester United: Romero, Young (c), Jones, Dalot, Darmian, McTominay, Fred (Chong 62), Pereira, Sanchez (Rashford 64), Mata (Fellaini 62), Lukaku.
Subs: Grant, Lindelof, Martial, Garner.
Goals: Mata 23 (PEN), Lukaku 45+4
Yellow: Chong

Reading: Jaakkola, Yiadom, Richards, Moore (c), Ilori (Aluko HT), Rinomhota, Kelly, McCleary (Barrow 61), Harriott (Méïté 76), Swift, Loader.
Subs: Walker, Gunter, O'Shea, East.
Goals:
Yellow: Yiadom

Referee: Stuart Attwell
Attendance: 73,918 (3,048 away)