Match ends, Rotherham United 0, Brentford 2.
Andre Gray and Nick Proschwitz gave Brentford a goal in each half as they secured a second win of the season.
Kirk Broadfoot hit the bar with a header for Rotherham before Paul Taylor was also denied by the woodwork for the home side.
Just before the interval, Alan Judge slid a pass through and Gray thumped the ball into the top corner.
Proschwitz scored Brentford's second in added time at the end when he tapped in from Jon Toral's cross.
Facing another team promoted from League One last season, the Millers almost moved in front when Broadfoot got his head to Kari Arnason's long throw but the defender's effort came back off the bar.
Taylor then beat goalkeeper David Button from outside the area but saw his shot bounce away off the crossbar.
Gray scored his first league goal since joining from Luton in the summer when he produced a powerful finish after being played through by Judge.
Matt Derbyshire should have equalised when he broke through on goal only to shoot weakly at Button.
But after a lengthy stoppage for an injury to Scott Hogan, Proschwitz produced a close-range finish from Toral's ball for his second goal since his move from Hull in the summer.
Rotherham manager Steve Evans:
"I think they have had a little bit of assistance from the referee,who I thought was poor all day. It seems to be every time we have him that he's poor.
"Goals win matches and Brentford have come and nicked the win. We have to earn our points and our performance was super. They have been battered from start to finish.
"But I don't include the striking department in that because we have missed a succession of chances."
Brentford manager Mark Warburton:
"It was a magnificent performance. We knew what to expect. They are a very organised side, with some very talented players and the physical talent of Alex Revell.
"We played very, very well with some great patches of play.
"Could we have been more clinical? Yes we could, and a special mention for David Button who has made two or three tremendous saves and really dominated the box in the second half."
- 8FrecklingtonSubstituted forWordsworthat 45'minutes
- 9RevellSubstituted forBoweryat 55'minutes
- 27DerbyshireSubstituted forBrandyat 67'minutes
- 27ButtonBooked at 71mins
- 6DeanBooked at 77mins
- 23JotaSubstituted forHoganat 67'minutesSubstituted forProschwitzat 83'minutes
- 19GraySubstituted forToralat 83'minutes
- Stuart Attwell
- Shots on Target
Second Half ends, Rotherham United 0, Brentford 2.
Goal! Rotherham United 0, Brentford 2. Nick Proschwitz (Brentford) right footed shot from the centre of the box to the centre of the goal. Assisted by Jon-Miquel Toral.
Attempt missed. Alex Pritchard (Brentford) right footed shot from outside the box is close, but misses to the left from a direct free kick.
Alex Pritchard (Brentford) wins a free kick in the attacking half.
Foul by Anthony Wordsworth (Rotherham United).
Attempt blocked. Nick Proschwitz (Brentford) left footed shot from the right side of the box is blocked. Assisted by Alex Pritchard.
Foul by Alan Judge (Brentford).
Ben Pringle (Rotherham United) wins a free kick in the defensive half.
Jonathan Douglas (Brentford) wins a free kick in the defensive half.
Foul by Febian Brandy (Rotherham United).
Foul by Jon-Miquel Toral (Brentford).
Jordan Bowery (Rotherham United) wins a free kick in the defensive half.
Attempt blocked. Paul Taylor (Rotherham United) left footed shot from the right side of the box is blocked. Assisted by Ben Pringle.
Attempt saved. Paul Taylor (Rotherham United) right footed shot from the right side of the box is saved in the bottom left corner. Assisted by Febian Brandy.
Attempt missed. Harlee Dean (Brentford) header from the centre of the box is high and wide to the left. Assisted by Alex Pritchard with a cross following a set piece situation.
Nick Proschwitz (Brentford) wins a free kick on the left wing.
Foul by Richard Smallwood (Rotherham United).
Attempt missed. Kári Arnason (Rotherham United) header from the centre of the box is high and wide to the right. Assisted by Ben Pringle with a cross following a corner.
Corner, Rotherham United. Conceded by Alan Judge.