Watford are through to the fourth round of the FA Cup after safely navigating a potential banana skin in professional fashion and with relative comfort as they beat League Cup semi-finalists Bristol City 3-0 at Vicarage Road.

Goals from Andre Carrillo, Troy Deeney and Etienne Capoue saw a strong Hornets side through, while Lee Johnson opted to field an understrength line-up with Tuesday’s trip to Manchester City firmly in mind.

Watford had been comfortably the better side for most of the first half without creating too many chances, but their efforts were to be rewarded in the 37th minute when Carrillo fired in his second goal in as many home games.

The hosts then looked to kill off the game after the restart and after Roberto Pereyra hit the woodwork following a good move, Deeney established daylight between the sides when he headed in a low Tom Cleverley cross.

Both sides had opportunities to score thereafter before the home side netted a late third when Capoue fired home after exchanging passes with Deeney.

The feeling ahead of the game was Marco Silva would name a strong side, but there was perhaps some surprise at just how strong it was as he made just three changes from the team selected for the 3-1 defeat at Manchester City.

In came Cleverley, Pereyra and, following his four-match suspension, Deeney as Ben Watson, Richarlison and Andre Gray dropping to the bench.

Lee Johnson was always going to make wholesale changes with a League Cup semi-final at Manchester City looming very large on the horizon and ultimately he decided on seven from the side that was thumped 5-0 at Aston Villa in the Championship on Monday.

The four to keep their place from that team were keeper Luke Steele, skipper Aiden Flint, fellow defender Horour Magnusson and mifielder Korey Smith. Indeed, seven of the Robins’ match-day 18 were Under-23 players.

After a fairly low-key opening, the Hornets created the first chance when Carrillo fed Daryl Janmaat to his right and the Dutchman stood up a cross to the back post where Deeney headed down and on target, but he was unable to generate sufficient power to trouble Steele.

The Hornets continued to dominate the opening exchanges against a City side defending increasingly deep, but they were unable to create another effort on goal until Abdoulaye Doucoure headed harmlessly over in the 12th minute.

Steele was forced into his next save two minutes later when Capoue let fly with a daisy-cutter from 25 yards, but the keeper was always behind it.

Steele then had to get up above Deeney to hold a Doucoure flicked header following a Cleverley corner from the right, before Janmaat came inside and his mis-hit shot broke for Pereyra, but again Watford were unable to get the better of the visiting keeper.

The Hornets’ build-up play had been largely patient and somewhat pedestrian at times, but as the midway point of the opening half they began to up the tempo with some quick and neat inter-passing in and around the opposition 18-yard box.

This led to the hosts winning a couple of more corners, the second of which saw Molla Wague have an on-target shot blocked.

The next opening came when Carrillo played a nicely weighted pass in behind the City defence for Cleverley to run onto, but Steele was quickly off his line to block.

Christian Kabasele picked up the game’s first yellow card on the half-hour for a foul on Smith, but two minutes later the centre-half was unable to force the ball past Steele after Doucoure had flicked on Cleverley’s latest corner delivery at the near post.

Pereyra was the next to see a shot blocked, having come inside off the left after Carrillo pinged a cross-field pass out to his teammate.

But the Hornets’ attacking endeavours were to be rewarded in the 37th minute when Pereyra laid the ball off to Carrillo in the area and he stepped past one opponent before drilling a low shot beyond Steele to make it 1-0.

The Robins had offered little going forward but Heurelho Gomes was forced into a watchful dive as Cauley Woodrow fizzed a low 25-yard drive wider of the keeper’s right-hand upright four minutes before the interval. But the Hornets went into the break deservedly a goal to the good, having looked comfortable for the most part.

The visitors made a change at the start of the second period as Smith was replaced by Marlon Pack, but it was their opponents who almost doubled their lead in superb fashion five minutes after the restart.

Following a pass by Doucoure, Carrillo upped the tempo as he drilled the ball out to his left to Pereyra, who again came inside, played a lovely one-two with his Peruvian teammate, before hitting a right-footed curler from the edge of the 18-yard box which beat Steele but not his crossbar. The rebound then fell for Capoue, who took a touch before hitting a rising drive which the keeper was equal to.

But the home side didn’t have long to wait for their second goal, as after Carrillo and Janmaat had combined down the right, Cleverley latched onto the loose ball by the byline, played in a low cross and Deeney got across his man to send a stooping header past Steele to make it 2-0.

City made their second change in the 62nd minute when Gustav Engvall replaced Matty Taylor, seconds after the striker had missed a very good chance to half the deficit when he sent a free header wide after being picked out unmarked by Lloyd Kelly’s cross from the left.

From missing a chance to make it 2-1, the Robins almost found themselves 3-0 down in the 66th minute when Janmaat clipped in a cross from the right and Deeney stole in to head the wrong side of Steele’s left-hand post.

Doucoure hit a half-volley over from the edge of the area after a clearing header had sat up invitingly for him before Silva opted to change things in the 69th minute as Richarlison and Jose Holebas came on for Carrillo and Pereyra, both of whom had enjoyed positive afternoons.

Following the changes, Marvin Zeegelaar pushed forward to the left side of midfield and he was to create the next opportunity with a cross which Wague headed over.

But it was the visitors who were to go closer as an under-pressure Engvall stabbed wide following Opi Edwards’ low delivery from the right, before Steele was extended by a Holebas piledriver after Doucoure had laid the ball inside to the retired Greek international.

Freddie Hinds replaced Woodrow with 13 minutes remaining and the young substitute was soon involved, hitting a low drive which Gomes held at the second attempt.

Watson came on for Doucoure for the final nine minutes of normal time and three minutes later the Hornets netted their third when Capoue played the ball into Deeney, who waited on the pass for his French teammate to make a positive move forward and the former Tottenham Hotspur man took the ball in his stride to fire past Steele to complete a good job done by the hosts.

Watford: Gomes; Janmaat, Wague, Kabasele, Zeegelaar; Cleverley, Doucoure (Watson 81); Carrillo (Richarlison 69), Capoue, Pereyra (Holebas 69); Deeney. Subs not used: Karnezis, Prodl, Gray, Okaka.

Bristol City: Steele; Vyner, Flint, Magnusson, Kelly; Edwards, Lemonheigh-Evans, Smith (Pack 46), Eliasson; Taylor (Engvall 62), Woodrow (Hinds 77). Subs not used: Fielding, Wright, Bakinson, Holden.

Bookings: Kabasele for a foul on Smith (30).

Attendance: 13,269.

Referee: Craig Pawson.