Didier Drogba cancelled out Bogdan Stancu's sixth-minute opener but Gala could not find a winner as they fell 11 points behind leaders Fenerbahce.
It was a disappointing result to finish a memorable week after Roberto Mancini's side booked their place in the Champions League knockout stages with a 1-0 win over Juventus in a match played over two days because of snow and hail in Istanbul.
Those exertions perhaps told as they lost ground on second-placed Kasimpasa too after they beat Besiktas 2-1.
Hugo Almeida fired Besiktas, who started Sunday in third, ahead after three minutes.
That was as good as it got for the visitors though as Halil Colak and Ezequiel Scarione won the game before Motta Ramon and Almeida saw red with eight minutes left.
Gaziantepspor beat Kayseri Erciyesspor 2-1.
Turgut Sahin and Cenk Tosun did the early damage before substitute Bilgi Ustun pulled a late goal back.