The spirit of football and sports rivalry were overshadowed Wednesday when a section of Fenerbahçe fans chanted "Vladimir Putin" after conceding a goal in a Champions League qualifying match against Dynamo Kyiv in Istanbul.
Ukraine's envoy to Turkey on Thursday expressed "sadness" over the chant, which hit particularly hard as the country has been ravaged by a Russian invasion.
Images on social media showed some Fenerbahçe fans singing the Russian president's name after Dynamo's Vitaliy Buyalskyi decided to celebrate his goal by celebrating in front of the home crowd.
The chants appeared to have been sparked after Buyalskyi made an eagle gesture with hands, which some fans believed to be a nod to Fenerbahçe's archrival Beşiktaş.
The Ukrainians won the match 2-1 after drawing 0-0 in the home leg played in Poland because of Russia's invasion.
"Football is a fair game. Yesterday Dynamo Kyiv were stronger," Ukraine's Ambassador Vasyl Bodnar tweeted.
"It is very sad to hear the words of support from Fenerbahce's fans for a Russian murderer and aggressor who bombed our country," Bodnar wrote.
"I am grateful to the friendly Turkish people for their support of Ukraine and for their consideration of the inappropriate actions of the fans."
Dynamo's Romanian coach Mircea Lucescu refused to attend the mandatory post-match press conference in protest.
"I did not expect such a chant," he said in a statement released to Turkish media. "It is a pity."
A group of Ukrainian citizens protested in Istanbul Thursday, demanding those fans be barred from Fenerbahçe's stadium.
Meanwhile, European football's governing body UEFA has launched an investigation into the incident.
A UEFA statement Thursday said the probe had been ordered following the "alleged misbehavior" of some Fenerbahçe supporters.
Turkey is generally popular among many Ukrainians because of its military support for Kyiv's Western-backed government.
The Ukrainian army has used Turkey's Bayraktar TB2 combat drones to attack Russian armored columns and slow the Kremlin's push into the Donbas war zone in the east.
Ukraine now has a "Bayraktar" radio station and the drones feature in popular songs.
The private company said Thursday it was donating another drone to Ukraine in response to a fundraising effort in Poland aimed at raising millions of dollars for the purchase of one of the unmanned aerial vehicles on Kyiv's behalf.
The Ukrainian ambassador thanked Turkey's drone makers in another tweet.
"Bayraktar will remain a symbol of friendship between our countries for many years," Bodnar wrote.