Ivory Coast began their AFCON journey with a Group E clash against Equatorial Guinea at the Stade de Japomba on Wednesday.
Captained by the former Whites man, Gradel's side went into the game clear favourites against one of Africa's smallest nations.
The forward opened the scoring with a sixth-minute screamer before the West African team held on to the lead to take a win from their first game of the tournament.
Gradel played a central role in Leeds' escape from League One more than a decade ago, signing for Leeds midway through the 2009/2010 season after an impressive spell on loan from Leicester City.
As Simon Grayson's Whites closed in on promotion, he graduated from bit-part appearances to the starting eleven, making a remarkable five goal contributions in the Leeds' final six games of the campaign before almost derailing United's fate on the last day of the season. In a make-or-break fixture against Bristol Rovers, Gradel was shown a straight red for stamping on Daniel Jones in the 34th minute leaving Leeds a man short to get the result needed to avoid relying on play-off success to secure promotion.
Fortunately, Gradel's moment of madness didn't prove decisive as Grayson's side came from behind to claim a 2-1 victory and a place in the Championship for the 2010/2011 season.
In the second tier, Gradel became a regular feature and a fan favourite at Elland Road. The Ivorian scored 25 goals and made 13 assists before departing for Ligue 1 side Saint-Étienne ahead of the 2011/2012 campaign.
Now, the 34-year-old is taking a break from service to top-flight Turkish side Sivasspor to bid for a third AFCON Championship for his home nation.
In the lead-up to the tournament, Gradel gave a touching tribute to his late father on social media.
"When I return, I will organise a tribute worthy of his name," Gradel wrote.
"I hope to come back victorious for him."
Shortly after kicking off his nation's AFCON campaign, Gradel opened the scoring for Ivory Coast, striking a clean first-time shot from outside the box into Equatorial Guinea 'keeper Manuel Sapunga's top corner.
The skipper gave an emotional celebration and a touching dedication in his post-match comments.
"It's a mix of emotion and joy at the same time," Gradel told BBC Sport.
"I am very happy to have scored for my father, the whole Ivory Coast and all Ivorians."