Rotherham ended their winless run with an impressive 2-0 victory over Bristol City.
Paul Warne's side had lost their last three matches and were without a win in six, but put on a strong first-half display to upset the promotion hopefuls.
Rotherham were ahead within four minutes, with Dan Barlaser picking out Crooks perfectly from a free-kick and the midfielder powering in a header.
City goalkeeper Daniel Bentley then had to be alert to push Smith's effort from the edge of the box behind.
Rotherham were in the ascendancy before the break and after a strong penalty shout for a foul on Matt Olosunde was dismissed, Crooks fired over a decent chance from the edge of the area.
They got their second after 41 minutes, however, with Olosunde holding his run to beat the offside trap and then picking out Smith, who poked in from close range.
An uneventful start to the second period certainly suited Rotherham more and it was they who had the first opening after the restart with Jamie Lindsay curling an effort wide.
Diedhiou's first real involvement was to volley at goal and force Johansson to make a save with his legs.
Rotherham substitute Freddie Ladapo was having much more of an impact and he twice troubled the City defence in a matter of minutes, with the second occasion seeing his shot diverted behind for a corner.
A neat move down the right almost saw Rotherham net a third but Lindsay's cross was volleyed into the side netting by Ben Wiles.
Rotherham went even closer to rounding off a perfect afternoon with Barlaser smashing a 20-yard free-kick at goal which Bentley had to instinctively punch over the crossbar.
Wells had the best opportunity in the six minutes of added-on time but his glancing header did not trouble Johansson and the Millers could celebrate a clean sheet as well as three well-deserved points.