CHARLTON ATHLETIC achieved Sky Bet Championship safety with a 3-1 win over the Hornets, who for the second time in four days found themselves reduced to 10 men and beaten on the road.
Callum Harriott broke the deadlock for the Addicks midway through the first half, but a sublime Troy Deeney volley pegged them back on the hour.
Ex-Watford midfielder Johnnie Jackson turned it home to restore the hosts’ lead with little more than 20 minutes to go, an advantage doubled when Harriott completed his brace with a sweetly-struck shot.
Albert Riera was shown a second yellow card with 11 minutes to go, as Watford ultimately fell to a third successive away defeat.
Beppe Sannino made five changes to the Hornets’ starting line-up, with the injured pair Joel Ekstrand (ankle) and Lewis McGugan (knee) replaced by Tommie Hoban and Sean Murray.
Marco Cassetti’s red card at Derby on Saturday ruled him out, so Essaid Belkalem came into the back-three for his first appearance since March 22 at Wigan.
Davide Faraoni took the place of Daniel Pudil, lining-up at right-wing back, leaving Riera to move to his favoured left-side position. Ikechi Anya replaced Mathias Ranegie in attack.
Jonathan Bond continued to deputise for Manuel Almunia (Achilles) in goal, and Academy scholar Alex Jakubiak retained his place on the substitutes' bench.
It was a lively atmosphere in the stands during the opening 10 minutes at The Valley, with Sky Bet Championship survival at stake for the Addicks, but there was little to report on the pitch other than Hornets wideman Faraoni requiring treatment for a knock.
Harriott fired over from close range, via a slight deflection off Faraoni, having been teed up by Chris Solly and Jordan Cousins on 13 minutes.
Faraoni was still visibly struggling, and Sannino opted to replace the ex-Inter Milan man with quarter of an hour played, Ranegie joining the Hornets’ attack and Anya dropping to right wing-back.
Bond was twice called into action – first requiring two attempts to collect a Johnnie Jackson free-kick, then keeping out the former Watford loanee’s header with a good near-post save – two chances which sandwiched a 17th minute Deeney drive that stung Ben Hamer’s palms.
Charlton were looking threatening on the attack and they took the lead 22 minutes in, Harriott advancing towards a back-tracking Watford back-line and arrowing a finely hit shot into the far corner from 25 yards.
The Hornets responded well though and but for a sprawling Hamer save to tip Deeney’s long-range effort behind, they might have found a 26th minute leveller.
From the resulting corner Daniel Tozser’s delivery was headed against the woodwork by Belkalem, then just after the half-hour a trademark Murray shot 30 yards from goal whistled just wide of the far post.
Anya played a teasing ball in from the right byline on 39 minutes which took Ranegie by surprise, bouncing off the Swedish striker’s chest before being scuffed behind by a Charlton defender.
Belkalem received the evening’s first yellow card for a foul on Lawrie Wilson, in the first of three added minutes at the end of the first half.
Gabriele Angella was introduced to the Hornets’ back-three in place of Lloyd Doyley seven minutes into the second period, with the Addicks once again the most dangerous side in the opening stages.
But it was strike of real quality which drew Watford level, Deeney pulling the ball out of the air and firing a stunning volley into the top corner from 25 yards to equalise on the hour, the number nine’s 24th – and possibly best – of the season so far.
Former Watford man Marvin Sordell was withdrawn for Jonathan Obika on 67 minutes, just moments before Anya played it inside to Deeney and the Hornets’ striker unleashed a rocket of a shot which flew just over the bar from the angle.
The hosts regained the lead on 69 minutes, Morgan Fox carving open the Hornets’ defence with a through ball and Addicks skipper Jackson nipping in front of Bond to poke past the Watford keeper.
Samba Diakite replaced Murray with quarter of an hour to go, but the Hornets were two minutes away from conceding a third.
Harriott was the man to make it 3-1, meeting Wilson’s cross with a superb first-time volley which nestled in the bottom corner for the Charlton winger’s second of the evening.
For the second game running Watford were reduced to 10 men, Riera dismissed on 79 minutes after collecting a second booking for a high tackle on Diego Poyet.
Double goalscorer Harriott was granted an extremely warm reception from the home crowd when replaced by Joe Pigott inside the final three minutes, then Solly made way for Andy Hughes in the closing stages.
Hoban skipped past a challenge in the Addicks’ box in injury time and played in Anya, who touched it towards goal but was denied by the assistant referee’s flag, as Watford left The Valley with nothing to show from their final away game of the season.
ADDICKS: Hamer (GK); Solly (Hughes, 90), Fox, Morrison, Dervite; Wilson, Cousins, Poyet, Jackson (C), Harriott (Pigott, 87); Sordell (Obika, 67).
Subs not used: Thuram-Ulien (GK), Wood, Petrucci, Ajdarevic.
Goals: Harriott (22, 77), Jackson (69)
HORNETS: Bond (GK); Doyley (Angella, 52), Hoban, Belkalem; Faraoni (Ranegie, 15), Battocchio, Tozser, Murray (Diakite, 75), Riera; Anya, Deeney (C).
Subs not used: Woods (GK), Merkel, Pudil, Jakubiak.
Goals: Deeney (60)