IVAN Calero was the late hero as his debut goal gave Derby County a 1-0 victory over Charlton Athletic in the second round of the Capital One Cup.
The Spaniard, signed on a free transfer in the summer, came off the bench to net an 87th-minute winner at the iPro Stadium.
Both sides made six changes following their Championship outings at the weekend.
The first chance went to Charlton after eight minutes.
George Tucudean's 25-yarder bounced awkwardly in front of Lee Grant but the keeper parried and then gathered the loose ball.
Franck Moussa's effort from outside the box was deflected over the bar, while Tucudean saw a goalbound volley blocked by Rams skipper Richard Keogh.
Derby grew into the game as the half went on and created a string of chances in quick succession.
Omar Mascarell's 32nd-minute corner was cleared as far as Johnny Russell and his volley bounced up to Keogh, who headed wide from eight yards.
Moments later, Leon Best showed some good skill to carve out a chance, only to see his fierce 20-yard drive tipped around the post by diving keeper Nick Pope.
From the resulting corner, Keogh nodded down to Jeff Hedrick, who drilled inches wide from an angle.
The home side kept up the pressure but were unable to make a breakthrough before the half-time whistle.
Best could not quite get on the end of Craig Forsyth's headed knock-down five minutes after the restart.
Russell then had a shot deflected behind, amid appeals for a handball that fell on deaf ears.
On the hour, Russell's low ball in from the left just evaded Simon Dawkins in the middle.
Derby made a triple change with 20 minutes to go.
Chris Martin was brought on, along with debutants Calero and Alefe Santos.
Mascarell, Dawkins and Russell made way as the Rams went to a 4-4-2 formation.
Martin curled a shot narrowly wide from 20 yards and saw a clever flick from a Santos cross land in the keeper's arms.
At the other end, Johann Gudmunsson's free kick from the right was tipped over by Grant in the 82nd minute.
Calero had a chance to break the deadlock five minute from time but his side-foot shot from 12 yards was too close to Pope.
He made no mistake a couple of minutes later, though.
Martin did brilliantly to retrieve the ball following a free kick into the wall and surged into the area before laying off to Calero, who smashed a right-foot shot into the corner of the net from 15 yards.
Martin also sealed the win late on but, first, his powerful drive was turned around the post by Pope, then his 30-yard free kick whistled just over.
Charlton threw everyone forward in search of an equaliser but the closest they came was a Morgan Fox effort in added time which was blocked behind.
DERBY COUNTY: Grant, Shotton, Keogh, Whitbread, Forsyth, Mascarell (Martin, 69), Hughes, Hendrick, Russell (Santos, 70), Dawkins (Calero, 70), Best. Other subs: Roos (gk), Christie, Rawson, Bryson.
CHARLTON ATHLETIC: Pope, Gomez, Bikey-Amougou, Morrison, Fox, Wilson, Cousins, Jackson (Buyens, 65), Harriott, Moussa (Gudmundsson, 79), Tucudean (Vetokele, 65). Other subs: Mitov (gk), Wiggins, Church, Ben-Haim.
REFEREE: G Salisbury (Lancashire).
ATTENDANCE: 16,367.
