Both the Hornets and Crystal Palace could mathematically be playing in the Premier League next season, but on current evidence it looks like Neil Warnock's Eagles could be the form horse to back in the play-offs.
Watford didn't deserve to lose 2-0 as they were the team more likely to score until Paul Ifill lashed in the opener.
But this second straight home defeat made it one win in 12 for Aidy Boothroyd's men, while three goals in six matches at Vicarage Road is another statistic no team wants to be taking into the end-of-season lottery.
Another statistic is that Watford don't lose when they take the lead and had Jobi McAnuff steered Tommy Smith's delightful early cross inside rather than just the wrong side of Julian Speroni's right-hand post, the outcome would probably have been very different.
The Hornets had a break when Jordan Stewart was in the right place to block Clinton Morrrison's acrobatic attempt on the line, but after that the home side dominated the chances and should have made at least one count.
McAnuff saw a volley deflected behind, Tamas Priskin should have done better than fire straight at Speroni, while after the restart, the Hungary international saw a header hit the woodwork after Darius Henderson nodded the ball back into the danger zone.
But if you don't take your opportunities you tend to get punished and that's exactly what happened.
With 20 minutes remaining, Watford failed to deal with a ball that was lifted back into their penalty area and substitute Ifill latched on to it in a flash after drifting inside Stewart before striking a left-footed shot that swerved away from Richard Lee.
Worse was to follow for the home side four minutes later when Morrison found Victor Moses, who turned Lloyd Doyley inside out before sliding the ball under Lee from the left side of the six-yard box.
It wasn't quite a smash and grab raid, but it was a win that maintains Palace's forward momentum.
Watford, by contrast, cannot get themselves out of reverse.