The men's swimming competition got underway on Saturday - the first full day of action at the fourth edition of the Islamic Solidarity Games - with Turkish swimmers laying down an early marker at the Baku Aquatic Centre.
Only five heats were held during a short morning session, in the men's 50m breaststroke and 400m freestyle.
Turkey's Huseyin Emre Sakci - who holds his country's short course records in the 50m, 100m and 200m freestyle - was the quickest man across the three 50m breaststroke heats, with a time of 28.09 seconds.
While 19-year-old Sakci triumphed ahead of Indonesia's Indra Gunawan in the second heat, his compatriot and defending champion Demir Atasoy claimed top spot in the third in 28.59.
Atasoy was one of the stars of the 2013 Solidarity Games in Indonesia, securing gold medals in the 50m and 100m breaststroke as Turkey finished second in the swimming medal table, with 11 gold, 11 silver and nine bronze.
The 29-year-old also holds Turkey's national record in the 50m breaststroke - 27.81 - and could be set for a fascinating battle with his young countryman Sakci if, as expected, both men reach the final.
Malaysia pipped Turkey to top spot in the medals table four years ago, and will be another nation to watch in spite of a fairly modest opening session.
Daniel Willia Henry Bego and Yeap Zheng Yang finished third and fifth in their respective 400m freestyle heats, but nevertheless qualified for this evening's final as Malaysia look to defend the gold medal won in 2013.
Jordan's Khader Ghetrich Baqlah set the quickest time of 4:00.13 across those two heats, just ahead of another Turk, Kaan Ozcan, and Aflah Prawira of Indonesia.
The swimming continues in Saturday's evening session, with several finals on the menu including the men's 200m backstroke and 400m freestyle, and the women's 200m individual medley and 800m freestyle.