Stefano Okaka had opened the scoring with a header from a corner, before Abdoulaye Doucoure cancelled out Mane’s wonderstrike before half-time.
And with a quick-fire double from Firmino and Salah looking set to hand Liverpool the victory, Miguel Britos bundled home an equaliser in stoppage time to burst the Reds’ bubble.
Speaking after the game, Mane lamented his side’s sloppy defensive work, struggling to cope with Watford‘s physical threat.
“I’m a little bit disappointed, we should defend better in this kind of game,” Mane told LFCTV.
The 25-year-old was arguably the Reds’ best player on the afternoon, and continuing his assessment of the result he stressed that Liverpool should be capable of defeating the Hornets.
“We’re all professional football players, so I think we’ll use this. It can happen in football,” he added.
“With all the respect to Watford, I think we should win. We had the better team.
“But still, it’s football: we’re going to accept it and forget it and try to be ready for the next game.”
The notion of building on Saturday’s performance with improvement in Tuesday night’s Champions League play-off clash with Hoffenheim was prevalent as Klopp’s squad took to social media, too.
“Disappointed we didn’t see the game out but still a lot of positives to take from it,” he told his followers. “Another big game for us coming up, thanks for the brilliant support once again.”
With a strong contingent of supporters backing Liverpool on Saturday, Wijnaldum, Alexander-Arnold, Henderson and Lovren all thanked the travelling Kop.
The hope will be that this is reflected in their display at the Rhein-Neckar-Arena on Tuesday night, as the Reds will need to be on their best form to seal a result against Hoffenheim.