Derby always had the edge as they stepped up the pace to inflict only Birmingham’s second home defeat under new manager Gary Rowett.
The Blues never recovered from an early strike by Ibe when the pacy winger, who had a short spell at St Andrew’s on loan from Liverpool, forced home a close-range shot.
Martin’s 22nd-minute goal direct from a free-kick was his 16th strike of the season – form which keeps Derby very much in the promotion race despite some recent indifferent results.
In poor playing conditions, Derby’s success was a holiday treat for the 3,000 travelling fans from the East Midlands who were treated to a third goal in the 78th minute from Forsyth, followed by a fourth from Russell two minutes from time.
With only one win from their previous four league games Derby were obviously intent on improving their recent record – a feat they achieved with a quality performance.
In steady rain the game took some time to come alive but in the 10th minute Derby stormed ahead as a result of some determined play by Ibe, who forced his way past Paul Caddis and Michael Morrison to blast the ball into the roof of the net from very close range.
The goal resulted in Birmingham abandoning their early policy of containment in an attempt to get back on level terms.
But Derby continued to have the upper hand with some high quality skill as demonstrated by Russell who cleverly side-stepped a Birmingham defender following an astute pass from Martin only to slam the ball into the chest of goalkeeper Darren Randolph.
With Derby so dangerous on the breakaway very little was seen of Birmingham’s bright youngster Demarai Gray as the County defence appeared solid against advance made by the opposition.
The result was that the only time goalkeeper Lee Grant was tested come from a long-range effort from David Cotterill.
The response from Derby was to immediately increase their lead. Russell, who led the Birmingham defence on a merry dance, went on a fast cross-field run only to be brought down by Stephen Gleeson on the edge of the D.
Derby’s leading marksman stepped up to dispatch the kick into the roof of the net with great authority for his 16th goal of the season in the 22nd minute.
There then should have been a third Derby goal. The fast moving Ibe outpaced the Birmingham defence and squared the ball to the unmarked Will Hughes, who slipped as he was about to make contact.
With the rain turning to persistent snow it did not deter Derby, while Birmingham found some belated attacking form with the introduction of both Nikola Zigic and Wes Thomas.
The double substitution had a marked effect with Thomas immediately testing Grant, while Randolph prevented a third goal when he saved Russell’s angled shot with an outstretched leg.
Birmingham were the more positive in the closing stages but the result was well and truly put out of their reach in the 78th minute when Forsyth collected a pass from Ibe to score with a long raking drive from outside the area.
Russell deservedly notched the fourth when he latched on to a blocked clearance to score with a low angled shot in the 88th minute.