Derby County boss Steve McClaren has admitted Rotherham United had struck fear into his team of Championship promotion-chasers.
The Millers were beaten 1-0 at the Ipro Stadium in their first game in the second tier for nine years but were looking good for at least a draw until Jeff Hendrick struck with just eight minutes to go.
McClaren, who was once manager of England, conceded: “We had one or two hairy moments.
“We knew Rotherham would make us work hard for the result.
“They had been beaten only four times in 34 games and have the confidence after winning promotion at Wembley last season.
“They are difficult opponents. Steve Evans has done a great job with them.
“He has got them organised and hard to beat. They are a threat at set-plays.”
The Millers should have snatched a draw in time added in front of English football’s biggest crowd of the day, 30,10
But Lee Grant saved superbly from Paul Green’s bullet header and then Kieran Agard’s shot.