Substitute Adam Le Fondre scored late on as Reading came from behind to overcome a battling Watford.
The comeback ensured Shaun Cummings' blushes were spared after he turned into his own goal in the 29th minute to put the hosts in front.
Jimmy Kebe struck back for Reading just before the break when he headed in Hal Robson-Kanu's cross from close range.
Then, with five minutes remaining, Le Fondre found the bottom corner to seal the win with a clever finish.
With seven of the last 11 games between these sides ending level this was expected to be a tight affair, despite high-flying Reading being in fine form with six wins in eight league outings before this match.
And Watford proved not to be fearful of Reading's lofty position as they took the lead midway through the first half, albeit with a slice of luck, when Cummings put the ball past his own keeper after failing to deal with Troy Deeney's cross.
As the hosts pushed for an equaliser as half-time approached, Reading struck on the counter-attack, with Robson-Kanu bursting down the left wing before crossing for Kebe to head in his second of the season.
Deeney wasted a couple of half chances after the break for the hosts but nobody really looked like grabbing a winner until Le Fondre replaced Simon Church in the 83rd minute.
Then, just two minutes later, Ian Harte's corner fell to the striker with his back to goal and he instinctively flicked the ball with the outside of his boot past Scott Loach to grab a dramatic winner.