Mark Robins hailed the discipline and quality of his side after their 4-2 victory against Leeds in the Johnstone's Paint Trophy.
The Millers, who have already beaten Sheffield Wednesday, Wolves and Southampton in the Carling Cup this season, secured their place in the quarter-finals with an impressive display at the Don Valley Stadium.
Robins said: "To beat Leeds feels great."
He added: "The way we did it was the really pleasing thing. We attacked them when we could and it was a really disciplined performance with some real quality in there.
"The team keeps getting better and that is what you hope for. Leeds aren't in the Championship, but at the same time they are a Premiership outfit and they have some quality players.
"Everybody played their part. They can all take a lot of credit from this game and it should give us a real shot in the arm."
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