Two goals in as many second-half minutes ensured that Watford manager Brendan Rodgers endured a miserable return to the Madejski Stadium as Reading closed the gap on Coca-Cola Championship leaders Wolves with an easy 4-0 win.
Left-back Chris Armstrong scored his first goal for the club to give the Royals a deserved lead before half-time in a game littered with unforced errors in freezing conditions.
Strikers Noel Hunt and Kevin Doyle then helped themselves to goals midway through the second period before Leroy Lita grabbed a late fourth as Watford capitulated thanks to some wretched defending.
The sides' previous meeting this season was blighted by the award of the now infamous 'phantom goal' which gave the Royals a 2-2 draw in September.
Unsurprisingly referee that day Stuart Attwell was not requested to appear this time as Andy D'Urso took charge but after Armstrong struck there was never any question of controversy playing a part this time round.
Reading went ahead when a chaotic scramble in the area was tidily finished by Armstrong in the 38th minute.
Twice Watford were offered chances to clear a bouncing ball in the area but after they declined Stephen Hunt smartly brought the ball under control and teed up the overlapping Armstrong who cleverly volleyed between Loach and the near post.
Reading's second came when Noel Hunt was given far too much time and span to lash past Loach from six yards for his 12th goal of the season.
Watford were guilty of terrible defending for the goal but outdid themselves just a minute later when Doyle made it 3-0. Kebe played in Liam Rosenior down the right and his cross was not cut out by Jack Cork in front of Loach to allow Doyle to flick in his 17th - and easiest - of the campaign from three yards.
Coppell had the luxury of bringing off his two goalscorers to give Lita a rare appearance at the Madejski as his side moved to within four points of the summit. Lita has just returned from a loan spell at Norwich and appears certain to leave the club before his contract expires in the summer but showed his class with two minutes remaining when James Harper played him through on goal and he clipped past Loach.
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