Olcan Adin poached a hat-trick as Gaziantepspor crushed Istanbul Buyuksehir 4-1 in the Super Lig.
The former Fenerbahce striker added to the early goal from Hurriyet Gucer as home side Gaziantepspor tightened their grip on fourth place in the table, which brings a UEFA Europa League place.
Gucer opened the scoring after seven minutes by sliding in to finish a skidding cross from the left, and Adin notched his opening goal in the 33rd minute when he turned in a team-mate's wayward shot from close range.
Filip Holosko headed a goal back for the visitors after 62 minutes, but the two-goal margin was restored three minutes later when Adin clipped a left-footed strike past Oguzhan Bahadir after a determined surge inside the penalty area. He sealed his treble from close range in the 71st minute after team-mate Cenk Tosun curled a 20-yard shot against the right post.
Gaziantepspor have a three-point cushion over Kayserispor, who were beaten 4-2 in a thrilling match away to Besiktas. Marcelo Zalayeta turned sharply to fire Kayserispor into a 22nd-minute lead, but the match turned with the introduction of Besiktas substitute Hugo Almeida in the 59th minute.
He headed in a fine equaliser two minutes later, and Fabian Ernst put Besiktas ahead in the 69th minute when he nodded in a free-kick fired in from the left flank. Ricardo Quaresma hit a brilliant third Besiktas goal, driving in from 25 yards with the outside of his right foot, before Selim Teber's penalty made it 3-2. Almeida had the final say, slotting home a minute from time
The league's bottom side, Kasimpasa, beat mid-table Manisaspor 1-0 with a goal from Fernando Varela in the 73rd minute, while second-bottom Konyaspor drew 0-0 with Antalyaspor.