Watford dealt their automatic promotion hopes a huge blow by scoring two own-goals in the second half to hand play-off rivals Crystal Palace victory.

The visitors led 1-0 at half-time through Marlon King's strike, but substitute Dougie Freedman scored at the second attempt after Ben Foster had saved his 54th-minute penalty, and Jordan Stewart and Jay DeMerit netted at the wrong end to ensure the Hornets' promotion rivals triumphed.

The home side's joy was tempered by what looked a bad injury to striker Andrew Johnson, who was carried off with an apparent head injury following a collision with Watford goalkeeper Ben Foster.

It was a game of few chances, although Watford - who are six points behind second-placed Sheffield United in the Championship and have played a game more - deserved to take the lead in the first half.

Gavin Mahon's excellent pass from inside his own half sprung the Palace offside trap, allowing King to compose himself, outwit goalkeeper Gabor Kiraly and slide home his 19th goal of the season.

Watford celebrated jubilantly - but Palace were almost level a minute later.

Clinton Morrison's 10-yard shot drew a fine save from Foster, and when Jobi McAnuff turned the ball back into the danger zone Watford defender DeMerit was there to hack the ball clear.

Palace were dealt a further blow at the start of the second half when England striker Johnson was carried off with a head injury after he had collided with Foster as they contested the ball.

The incident stopped play for nearly five minutes - but, remarkably, Palace were in front within 10 minutes of their talisman's departure.

In the 54th minute, referee Mike Thorpe awarded a penalty for DeMerit's foul on McAnuff, and Freedman - who had replaced Johnson - slotted in the rebound after Foster had saved his initial spot-kick.

And six minutes later, Watford were distraught when Stewart - under little pressure - headed Fitz Hall's long throw from the right into his goalkeeper's right corner.

Between Palace's goals, King took advantage of some slack Palace defending to race onto a long clearance from Foster and beat Kiraly - but this time Darren Ward was in the right place to clear the danger.

Watford struggled to make headway after falling behind, and four minutes from time their misery was complete when DeMerit steered Tom Soares' cut-back from the right into his own goal from six yards.

Teams:

Crystal Palace Kiraly, Ward, Popovic, Boyce, Fitz Hall,Watson (Riihilahti 86), Hughes (Leigertwood 90), McAnuff,Soares, Johnson (Freedman 50), Morrison.

Subs Not Used: Speroni, Reich.

Booked: Watson.

Goals: McAnuff 55, Stewart 59 og, DeMerit 86 og.

Watford Foster, Stewart (Bangura 86), Doyley, Mackay, DeMerit,Eagles (McNamee 83), Mahon, Young, Spring, King, Henderson.

Subs Not Used: Chamberlain, Chambers, Carlisle.

Goals: King 28.

Att: 18,619

Ref: M Thorpe (Suffolk).