The former Atletico Madrid attacker, who joined the East Midlands side in the summer, scored the only goal of the game as a resilient Arsenal side dealt with the attacking bombardment from Derby incredibly well.
The Rams, who could have been three or four goals up before they found their opener had it not been for some outstanding defending and the woodwork, gave a great account of themselves as they moved above the Gunners and into second in the U-21 Premier League second-tier table. However, it was largely Ivan Calero who won the plaudits on the Arsenal website.
On the Spaniard's first-half performance, Arsenal.com reported : ''Calero - signed from Atletico Madrid last summer - caused Arsenal problems through the first half. He set up Callum Guy on the edge of the box, but the midfielder smashed well over.''
In the second-half, where the forward finally got his reward and netted the goal, the report reflected on the youngster's confidence: ''Arsenal failed to react to the warnings and were fortunate when former Gunner Alban Bunjaku’s shot deflected over, but they were punished moments later when Calero swept the resulting corner in from close range.
''The Spain Under-19 winger looked full of confidence and would have doubled his and Derby’s tally were it not for Iliev’s reactions and a sliced half-volley.''
Can Ivan Calero have an impact in the promotion race for Derby's first-team?
Although the Spaniard has been on the periphery of the first-team squad this season, it seems highly unlikely that he will have any part to play this season as the Rams get ready for their most important Championship run-in in almost decade.
Earlier in the season, before the Rams added the likes of Jordon Ibe then Jesse Lingard and Tom Ince, Calero was used as an impact player from the bench and actually netted an emphatic winner on his debut in the League Cup against Charlton to send Steve McClaren's men into the next round.
However, since the promotion race heated up, the youngster has rarely been named on the bench and looks further away from the first-team squad now than at any other point this season despite his form.
Nevertheless, given his obvious ability and potential, the youngster could be in a much better position to make an impact next season regardless of which division Derby find themselves in after the race for promotion comes to a conclusion.
At 19, the Spanish youth international still has a lot of time to break into the first-team and shouldn't be rushed as it seems the Rams could have a special prospect on their hands.