Frustration was again the over-riding emotion at Vicarage Road as Watford dropped more points in their quest to strengthen their play-off bid as they had to settle for a 1-1 draw against fellow top-six rivals Blackburn Rovers.

Although the Hornets had to come from behind to earn a point, they will reflect on opportunities not taken by Ismael Kone and Ismaila Sarr either side of Wesley Hoedt marking his debut with an equaliser.

Watford had started well and were playing some attractive build-up play through the thirds, only to fall behind when Sarr, Hoedt and Daniel Bachmann all played their part in allowing Bradley Dack to give the visitors the lead.

Joao Pedro had the best of the Hornets’ first-half opportunities when he fired narrowly wide following a defensive lapse, but the hosts really should have levelled when Kone somehow failed to convert a Matheus Martins cross at the far post after the break.

The Hornets did deservedly level when Hoedt fired home after a Ken Sema free-kick had been half-cleared, and almost immediately they could have gone in front when Sarr headed over from close range after goalkeeper Aynsley Pears had parried a Sema shot.

While Watford's effort could not be faulted and the biggest plus was several players returning from injury, it was another performance in which the home side didn’t convince and failed to impose themselves against savvy Championship opposition for large enough periods.

Slaven Bilic made three changes to the side that disappointingly let a two-goal lead slip and was pegged back to a 2-2 draw at Reading last weekend.

Craig Cathcart missed out with a groin injury and was replaced by debutant Hoedt, Kone replaced Leandro Bacuna in midfield and Joao Pedro made his return to the starting XI – and was named in captain – in preference to Keinan Davis.

There was more encouraging news on the bench with Imran Louza, Tom Cleverley, Sema and Christian Kabasele all deemed fit enough to be involved following their respective injury lay-offs.

Having gone 27 league games without drawing a league game, just like the proverbial London bus, Blackburn had finished with honours even in their previous two matches.

Boss Jon Dahl Tomasson made two changes from Monday’s 0-0 draw with Wigan Athletic; Tyler Morton and Tyrhys Dolan replacing John Buckley, who was on the bench, and Jack Vale.

The contest started promisingly with both teams looking to attack, the visitors having the first effort in the fifth minute when Sorba Thomas drove a shot over the bar from distance.

Watford responded three minutes later when Pedro, dropping into more of a right-back position, spotted the run of Mario Gaspar into the penalty area but the Spaniard chose to go it alone and fired over the top.

Hoedt was already catching the eye with his passing ability as the game settled down, with the hosts getting on top in terms of possession, and in the 15th minute Pedro played a one-two with Martins before almost effortlessly gliding forward and was a defender’s outstretched leg away from serving up a gilt-edged chance for Henrique Araujo.

Watford were beginning to tick, their next opening coming when Kone intercepted a pass and slipped in Pedro, who advanced to the edge of the area before hitting a right-footed shot which Pears was able to gather without too much difficulty.

Daniel Bachmann wasn’t unduly troubled by a Morton header from a free-kick that was drifted in at the other end – but with their next attack Rovers took the lead.

The visitors worked the ball from left to right before Thomas slipped a pass inside Hassane Kamara to Joe Rankin-Costello, who had been allowed to continue his run forward by Sarr. Hoedt was slow to react as the right-back fired in a shot which Bachmann got down to at his near post, but pushed back into play and Dack took a touch before calmly finishing.

Thomas picked up the first yellow card in the 31st minute for an overly forceful challenge on Kamara, but moments later the Hornets spurned a great chance to equalise when Travis’ attempted pass was partially intercepted by Kone into the path of Pedro, who was in plenty of space on the edge of the area but pulled his right foot shot just the wrong side of Pears’ right-hand post.

Hamza Chodhury levelled up the card count in the 36th minute when he was adjudged to have tripped Rankin-Costello, but the Hornets were to create another chance to level before the interval when Martins slipped in Araujo on the right side of the area and he pulled the ball back for Sarr, but the joint top scorer was unable to put his attempted finish wide of Pears.

Not fort the first time in recent matches, the half ended with frustration being directed at the referee after he let an off-the-ball challenge on Ryan Porteous go unpunished, before Gaspar needed treatment on a facial injury after coming off worse as he sought to beat Pears to a Kamara delivery.

Bilic opted to make a change at the break, bringing on Davis for Araujo, and the hosts had their first semblance of an opening when Sarr did well to accelerate away down the left, avoiding the challenges of both Morton and Hayden Carter who both slid in to no avail, before finding Martins, but the Brazilian’s first touch was heavy and the chance was lost.

Sarr then took matters into his own hands, cutting infield before unleashing a fiercely-struck drive which Pears held at the second attempt, but Watford really should have been level in the 56th minute.

Martins was given a second bite at the cherry after his corner failed to beat the first defender and this time he played in a much better cross which Davis challenged Pears for and the ball broke for Kone coming in at the far post, but the Canadian seemed almost surprised by the opportunity and failed to find the target from close range with the goal at his mercy.

Pears was tested again by a well-struck long range effort from Kamara, before the referee’s patience finally ran out and he booked Rankin-Costello for time wasting at a throw.

Both sides made changes on the hour; Buckley and Sam Gallagher replacing Morton and Thomas for the visitors, while Sema made his return from injury in place of Martins.

Dack had the ball in the net for a second time at the midway point of the second half following a free-kick, but the flag was already up for offside.

Cleverley became another injury returnee in the 71st minute when he replaced Choudhury – and three minutes later the Hornets were finally back on terms.

It originated from a surging run from Porteous that saw him fouled on the right angle of the penalty area. Sema played the free-kick deep into the six-yard box to the far post, it was headed partially clear, but only as far as Hoedt who hit a left-footed half-volley back through a crowd of legs to mark his debut with a goal.

Having equalised, Watford spurned a great opportunity to take the lead moments later when they broke down the right through Gaspar, he found Sema who checked back inside before hitting a stinging drive which Pears could only parry up in the air, but Sarr put his follow up header over the top from close range.

Both sides then made a double change; Ryan Hedges and Sammie Szmodics coming on for Dack and Ben Brereton Diaz, before Bilic rolled the dice again and brought on Louza and Britt Assombalonga for Kone and Pedro.

The Hornets head coach was booked with five minutes of normal time for protesting at the linesman as Blackburn made their final change, with Callum Brittain replacing Rankin-Costello.

Five minutes of added time afforded both sides hope of finding a winner, but much of the wind had gone out of the Hornets’ attacking sails since Pedro had gone off and they were able to muster another opportunity.

Watford: Bachmann; Gaspar, Porteous, Hoedt, Kamara; Choudhury (Cleverley 71), Kone (Louza 79); Martins (Sema 60), Pedro (Assombalonga 79), Sarr; Araujo (Araujo 46). Subs not used: Hamer, Kabasele.

Blackburn Rovers: Pears; Rankin-Costello (Brittain 86), Carter, Wharton, Pickering; Travis, Morton (Buckley 60); Thomas (Gallagher 60), Dack (Hedges 75), Brereton Diaz (Szmodics 75); Dolan. Subs not used: Hilton, Phillips.

Bookings: Thomas for a foul on Kamara (31); Choudhury for a foul on Rankin-Costello (36); Rankin-Costello for time wasting (59); Bilic for protesting (85); Kamara for a foul on Dolan (90); Gallagher for dissent (90).

Referee: Jeremy Simpson.