Mariappa's bizarre own goal is lifeline for Brighton in relegation fight against Watford
A late own goal by Watford's Adrian Mariappa ensured the points were shared in a 1-1 draw as Brighton earned a another vital point in their battle to avoid relegation.
Abdoulaye Doucoure, who scored an own goal when the sides met on the opening day of the season, capitalised on a loose ball before driving the ball expertly past Mathew Ryan.
Just as Watford looked to be heading for a crucial victory, Alireza Jahanbakhsh - who was introduced as a second half substitute - crossed and it was turned into the roof of his own net by Mariappa to level the tie with just over 10 minutes remaining.
The Hornets had suffered successive defeats against Aston Villa and Everton in the Premier League before the trip to the south coast, and Pearson's side remain in the bottom three despite claiming a point at the Amex.
The Seagulls remain without a win - or a clean sheet - in the Premier League this year, but have moved one point further away from the drop zone.
Brighton started the brighter of the two sides, and Glenn Murray, selected once again ahead of Neal Maupay, had a chance from a Solly March cross, but his headed effort lacked power and did not trouble Ben Foster.
The home side were caught out in the 19th minute and Watford made the most of a misplaced pass from Aaron Mooy to take the lead with their first shot of the match.
The ball fell to Doucoure who drove his way through the Seagulls defence before firing a powerful effort past Ryan in the Brighton goal.
Brighton struggled to get going in the midfield after going behind, and had difficulties creating chances in the later stages of the first half.
Watford had a chance to double their lead in the 36th minute, after Troy Deeney won the ball from Shane Duffy, before passing to Doucoure, but his effort was blocked by the Brighton defence.
Brighton came close to levelling the match at the start of the second half, but Ezequiel Schelotto's ball across the box was just ahead of the sliding Murray at the far post.
The home side continued to look for the equaliser, but struggled to get the ball past the resolute Watford defence.
Mooy so nearly levelled the tie in the 77th minute for the home side, but Foster made a crucial save to deny the Australian his third goal of the season with an outstretched leg.
Just moments later, the home side found the equaliser, when substitute Jahanbakhsh's cross was blasted past Foster and into his own net by Mariappa, who was under no pressure at the far post.
ALBION: Ryan; Schelotto (Jahanbakhsh 73), Dunk, Duffy, Burn (Maupay 57); March, Mooy, Propper, Trossard; Gross (Alzate 61); Murray.
SUBS NOT USED: Button (GK), Webster, Bernardo, Connolly.