Miguel Britos scored a dramatic injury-time equaliser as Watford claimed a 3-3 draw in a thrilling Premier League opener against Liverpool at Vicarage Road.

Watford took a 2-1 lead into the half-time break after strong first half showing, which saw Stefano Okaka and Abdoulaye Doucoure score either side of Sadio Mane’s leveller.

The game turned in Liverpool's favour early in the second half as Roberto Firmino’s penalty and a debut goal for Mohamed Salah put the visitors ahead.

With time all but up, Britos forced the ball over the line after a Richarlison’s effort had cannoned back off the bar to snatch a point at the death.

Watford will look to build on the result when they travel to Bournemouth for the maiden away outing of the campaign next Saturday.

Liverpool’s preparation for the season opener was marred somewhat by the ongoing transfer speculation surrounding Philippe Coutinho, who has been the subject of a reported £90 million bid from Barcelona and has asked to leave Merseyside.

Watford, meanwhile, have enjoyed an altogether more productive week with the arrival of Brazilian Richarlison and a record £18.5m capture of Andre Gray.

The former Burnley man had to make do with a place on the bench as Marco Silva opted to start with Okaka in a lone striking berth.

His decision would pay off with less than 10 minutes on the clock as the burly centre-forward bundled the hosts into the lead from a corner.

Okaka had been involved in winning the set piece, sending Roberto Pereyra clear before the winger’s shot deflected wide for a corner.

The resulting delivery from Jose Holebas was perfect in its execution and found Okaka at the near post to head beyond Simon Mignolet from close-range.

It was the standout moment of a performance full of power and purpose from the 28-year-old who looked intent on making an impression from the off.

What little Liverpool had managed to muster had been propelled with ease by Watford until just before the half hour when an incisive move cut their defence open.

Mane worked the ball out wide, continued his run towards the right channel and received a delicate flick round the corner from Emre Can.

With just Heurelho Gomes to beat the winger opened up his body and curled into the far corner with consummate ease.

Parity would last only a matter of minutes, however, as Watford went back ahead through Doucoure.

The midfielder was involved throughout the move and played a neat through ball into Tom Cleverley on the right wing.

With Okaka closing in, Cleverley’s low cross was only partially cleared and broke to Doucoure, who had made a smart run to the back post, to pass into an empty net.

The lead was no more than the hosts deserved for a strong first half showing, which had seen Silva’s men outfight Jurgen Klopp’s across the park.

Liverpool went within inches of wiping out the advantage on the stroke of half-time, but Mane, who was the Reds best player in the first 45 minutes, could only glance a header wide from Roberto Firmino’s corner.

The second half brought with it an early blow for Watford as Pereyra pulled up with what appeared to be a groin injury.

He made way for Richarlison, who showed some bright sparks during his first outing in Watford shirt.

All of Watford’s fine work was undone within the space of two second half minutes as Liverpool struck twice to go ahead.

The first came from the spot after Gomes brought down Salah to allow Firmino to calmly slot into the bottom left corner from 12 yards.

Firmino turned provider moments later after simple lofted ball bypassed the Hornets’ defence and sent the Liverpool number nine clear.

The Brazilian lifted a delicate chip over the onrushing Gomes and Salah tapped in from under the crossbar.

Watford were clearly shaken by the double blow and could easily have slipped further behind as Liverpool began to control proceedings.

The Anfield club went close from two corners as Trent Alexander-Arnold’s fine delivery proved effective.

Firstly the Reds rattled the bar and then it took a fine stop from Gomes to deny Dejan Lovren’s glancing header.

Watford’s attempts to get back into the game saw Gray introduced from the bench and more numbers committed forward late on.

They rewarded for their endeavour in the third minute of injury time when a near post corner fell to Richarlison and he fired at goal.

His effort was off target but Simon Mignolet inadvertently turned onto the bar, and Britos was on hand to score and lift the roof off the Vic on a pulsating opening day.

Watford: Gomes (C); Janmaat (Femenia 18), Britos, Kaboul, Holebas, Doucoure, Chalobah, Cleverley, Pereyra (Richarlison 48), Amrabat, Okaka (Gray 63)

Subs not used: Pantilimon; Prodl, Watson, Capoue

Liverpool: Mignolet; Alexander-Arnold, Lovren, Matip, Moreno, Henderson (C), Wijnaldum, Can, Salah (Milner 86), Firmino (Origi 80), Mane.

Subs not used: Karius; Gomez, Grujic, Klavan, Solanke