Besiktas remain joint-top of the Turkish Super Lig after they beat Trabzonspor 2-0 on Sunday and Galatasaray responded with a victory at Akhisar Belediye a day later.
An intriguing battle for the title looks set to go down the wire, with Slaven Bilic's side only ahead of their city rivals on goal difference with five games remaining.
Demba Ba scored just after coming off the substitutes bench to put Besiktas in front at Trabzonspor and Mustafa Pektemek sealed a precious victory deep into stoppage time.
Bilic's men have now won their last three games and a clash with Galatasaray in their penultimate game of the season could be decisive.
Burak Yilmaz was Gala's match-winner, scoring twice in the space of 12 first-half minutes to move Hamza Hamzaoglu's side level with the leaders again.
Fenerbahce remain only a point adrift of the top two, but the champions had to overcame a scare to see off bottom side Balikesirspor in a 4-3 thriller on Saturday.
Balikesirspor must have been fearing the worst when Caner Erkin put the home side in front, but Issac Promise and Ante Kulusic put them in front before Diego made it 2-2 with only 26 minutes played.
Fenerbahce were stunned again when Berkan Emir restored the visitors' advantage, but Moussa Sow levelled just before half-time and struck again after the break to secure all three points.
Balikesirspor's situation looks bleak and the same applies for Kayseri Erciyesspor, who squandered a two-goal lead to lose 3-2 at home to Sivasspor on Monday.
Sivasspor trailed 2-1 with two minutes remaining, but Burhan Eser struck twice to stun the hosts and move his side 10 points clear of the relegation zone.
Karabukspor enhanced their chances of avoiding the drop by securing a 2-0 win over Rizespor which ensured they are just four points behind their opponents, while Bursaspor were hammered 5-3 at Kasimpasa.
Eskisehirspor moved a point closer to safety by drawing 1-1 at Istanbul Basaksehir. Mersin Idmanyurdu were 3-1 winners over Konyaspor and Gaziantepspor were consigned to a 3-0 home defeat by Genclerbirligi.
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