Watford's poor home form looks set to continue as Kaspars Gorkss's early goal has given Reading the lead.
Gorrks converted Jordan Obita's cross to give the Royals the advantage, which they have managed to hold on to.
The away side's best chances have come from crosses, with the returning Jobi McAnuff looking particularly lively in the first period.
Watford have created opportunities from out wide as well, although so far they have failed to convert and find themselves a goal behind at the break.