Match ends, Watford 3, Rotherham United 0.
Watford maintained their bid for automatic promotion as Odion Ighalo scored twice in a comprehensive win over struggling Rotherham.
The striker has now scored 14 goals in his last 11 appearances and his side are six points off Championship leaders Derby.
Ighalo pounced on a slip by Kari Arnason to open the scoring before Troy Deeney slotted in after the break.
Ighalo tapped in after goalkeeper Adam Collin's fumble to complete the win.
Rotherham have now won just two of their last 12 games and are three points above the relegation zone.
The Millers could have been on the wrong end of an even heavier score line but for the athleticism of Collin, who did well to deny Almen Abdi, Deeney and Joel Ekstrand in the first half.
The visitors had chances themselves, with Watford goalkeeper Heurelho Gomes denying Matt Derbyshire as the former Nottingham Forest man went clear through before Craig Morgan headed straight at the Brazilian.
But the game was effectively over as a contest after the break.
First Ekstrand squared a rebound from Daniel Tozser's free-kick into Deeney's path for the latter to score on 54 minutes and Collin spilled Miguel Layun's shot at Ighalo's feet two minutes later.
Watford manager Slavisa Jokanovic: "It was a complicated game for us, especially after the first 45 minutes when we weren't particularly happy.
"After the second goal, everything started to be easier for us, we scored one more and we could have scored more, so I must be happy with our performance.
"Everything [Odion Ighalo] touches is finishing in the net and he is helping us so much. He is an important guy for us at this moment, he's always working hard."
Rotherham manager Steve Evans: "If you make big errors you get punished in the Championship if you come to a club with the players that Watford have got.
"Kari Arnason, slipping and falling over, I don't think you'll see that again in the Championship this season, but we've been done by individual errors.
"I've just been in the dressing room and the players concerned accept it's individual errors and it probably falsifies the last 15 or 20 minutes where Watford have a bit of the ball, with the quality they've got and they've got the freedom to express themselves."
- 7LayunSubstituted forMunariat 68'minutes
- 9DeeneySubstituted forForestieriat 84'minutes
- 24IghaloSubstituted forVydraat 75'minutes
- 4ArnasonBooked at 53mins
- 33SmallwoodBooked at 76mins
- 15MilsomSubstituted forWardat 65'minutes
- 23SammonSubstituted forHammillat 75'minutes
- 27DerbyshireSubstituted forClarke-Harrisat 88'minutes
- Andy Davies
- Shots on Target
Second Half ends, Watford 3, Rotherham United 0.
Almen Abdi (Watford) hits the left post with a left footed shot from the centre of the box. Assisted by Ben Watson.
Attempt saved. Jonson Clarke-Harris (Rotherham United) left footed shot from outside the box is saved in the bottom right corner. Assisted by Danny Ward with a headed pass.
Attempt saved. Matej Vydra (Watford) left footed shot from the centre of the box is saved in the centre of the goal.
Fernando Forestieri (Watford) wins a free kick on the right wing.
Foul by Ezekiel Fryers (Rotherham United).
Foul by Almen Abdi (Watford).
Richard Smallwood (Rotherham United) wins a free kick in the defensive half.
Attempt missed. Paul Green (Rotherham United) header from the centre of the box misses to the right. Assisted by Ezekiel Fryers with a cross.
Attempt missed. Paul Green (Rotherham United) right footed shot from the left side of the box misses to the right.
Attempt saved. Jonson Clarke-Harris (Rotherham United) left footed shot from the right side of the box is saved in the bottom right corner.
Substitution, Rotherham United. Jonson Clarke-Harris replaces Matt Derbyshire.
Corner, Rotherham United. Conceded by Craig Cathcart.
Attempt blocked. Matt Derbyshire (Rotherham United) right footed shot from the centre of the box is blocked. Assisted by Kári Arnason with a cross.
Corner, Rotherham United. Conceded by Joel Ekstrand.
Attempt saved. Adam Hammill (Rotherham United) right footed shot from outside the box is saved in the bottom left corner. Assisted by Danny Ward.
Substitution, Watford. Fernando Forestieri replaces Troy Deeney.
Attempt missed. Almen Abdi (Watford) left footed shot from the centre of the box is too high. Assisted by Troy Deeney with a cross.
Corner, Watford. Conceded by Craig Morgan.