Derby too strong for Cardiff despite David Marshall heroics
Derby found a way past an inspired David Marshall to beat Cardiff 2-0 through second-half goals by George Thorne and Andreas Weimann which secured a fifth successive home win.
The Cardiff goalkeeper made a string of outstanding saves in the first half but was beaten by Thorne's clinical finish 10 minutes after the break before Weimann pounced on a rebound to condemn the visiting side to only a second defeat in nine games.
Cardiff had conceded only three goals in their previous eight matches but Marshall had to get quickly down to his right in the sixth minute to keep out a Tom Ince shot from the edge of the penalty area.
Marshall was relieved to see a Jacob Butterfield drive bounce to safety off his legs two minutes later but there was a half chance for Cardiff in the 10th minute when Kenwyne Jones was crowded out as he shaped to shoot.
Derby had a great chance in the 15th minute when Cyrus Christie went round Scott Malone and picked out Weimann whose shot from 15 yards was parried by Marshall plunging to his right.
Scott Carson rescued the home side in the 24th minute when Jones muscled his way between the central defenders and set up Craig Noone whose drive from 12 yards was acrobatically beaten away by the former England goalkeeper.
That signalled a sustained period of Derby pressure that tested Cardiff's organisation and defensive discipline to the full, with Marshall again doing well to drop on a deflected Thorne shot.
Cardiff had an escape at the start of the second half when Marshall sliced a clearance behind and Bradley Johnson's glancing header from Butterfield's corner was cleared off the line by Joe Ralls.
The visitors were struggling to keep hold of the ball although a promising break by Noone on the right was halted by a Johnson trip which earned the midfielder a fifth yellow card of the season, meaning he faces an automatic one-match suspension.
But the goal Derby had been threatening arrived in the 55th minute when Ince played the ball into Martin who cleverly fed it into the patch of Thorne who drove a low shot into the bottom left corner.
Derby could have scored again a minute later when Butterfield put Martin through but Marshall spread himself to turn the ball over the bar and keep his side in the game.
The Cardiff captain was beaten for a second time in the 76th minute when he could only parry a low shot from just inside the area by Thorne and Weimann drove the loose ball under his body to put Derby firmly on course for another three points at the iPro Stadium.
Cardiff kept going but Jones and substitute Sammy Ameobi wasted chances to subject Derby to a nervy finale by heading over the bar from the edge of the six-yard box.