Chelsea took the lead early on via a wonderful Pedro Rodriguez strike from outside the box that hit the upright and went into the net.
The goal came as a result of a corner which shouldn’t have been given as the ball came off Eden Hazard’s heel.
Watford manager Marco Silva is unhappy about the decision and complained after the game. He said: “Last week was the penalty. Everybody knows it is not a corner, it was a goal kick.”
He then added that the result was unfair on his team.
He said: “We didn’t deserve the result. We started very well, we reacted to the goal well and in the first 25 minutes of the second half we played really well.
“We scored the second goal. We had the chances to kill the match and more chance to control. When you miss the big chances Chelsea have quality players. But a really unfair result.”