Basaksehir have started to show some fragility after a faultless start to the season, while Istanbulspor are beginning to find their feet back at the top table of Turkish football.
Match preview
Basaksehir were back on form with a thoroughly convincing 3-0 success over Rigas Futbola Skola in the UEFA Europa Conference League on Thursday, but there will be tougher tests to come than what was put in front of them by the Latvian minnows in midweek.
A tougher test will surely be provided by their nearby rivals who have performance stoutly against fellow Istanbul-based clubs so far, and a 2-0 loss to Sivasspor in their last league outing raised alarm bells at how important it is not to get too distracted by Europe or to not underestimate sides, especially at home.
However, that should not take away how much of a brilliant start to the campaign they have made on two fronts, as the Sivasspor defeat was their first in seven months.
Emre Belozoglu's side find themselves in a strong position just one off the summit with a game in hand in what is becoming an incredibly tight battle near the top, as just one point separates the top seven.
Basaksehir's 11 league goals have been spread out among 10 players which does have its benefit that the goals are being spread around the team, but there is no player at the club showing any consistency or ruthlessness in front of goal, something they have lacked since Edin Visca left for Trabzonspor.
That is why their superb defensive record remains so important because they do not score enough, and it is showing this season again just like it did last season, when they finished fourth despite having the joint-best record in the division, while this season they have yet to concede in Europe and have kept six clean sheets in eight Super Lig matches.
Therefore, Istanbulspor may have their work cut out to break down such a resolute backline, but as mentioned earlier, their record against other Istanbul clubs so far can be something for them to take into this game.
In their first appearance at this level since 2004-05, they have already come from behind twice to snatch a point off Besiktas, and they followed that up with a fantastic win away to Fatih Karagumruk two weeks ago.
This fixture may suit the Super Lig newcomers, as their away form has been significantly stronger with seven of their eight points coming on the road, but taking just one point from four home games so far is a cause for concern in the long term.
They will be boosted by the return of Valon Ethemi, who started his first game in almost a month last week, and after being instrumental in their promotion, the Macedonian has four goal contributions in just four starts this season.
The league looks split in half already as eight points separates seventh and 11th after just nine gameweeks, but sitting in 13th represents an impressive start for Istanbulspor despite defeat to Ankaragucu last week.
Istanbul Basaksehir Turkish Super Lig form:
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Istanbul Basaksehir form (all competitions):
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Istanbulspor Turkish Super Lig form:
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Istanbulspor form (all competitions):
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Team News
Basaksehir have recently welcomed back both Leo Duarte and Patryk Szysz after short-term injuries, as the duo were named among the substitutes for the match against RFS, with Szysz given a 10-minute runout at the end.
Mesut Ozil remains out injured, but their midfield options in the league will be bolstered by the return of captain Mahmut Tekdemir who has served his suspension following a sending off against Karagumruk, however he did still feature in both ties against RFS over the last two weeks.
All of Sener Ozbayrakli's appearances for Basaksehir so far this season came in UECL qualifying, but the right-back could be fit enough to return to the matchday squad here, however there is a battle between Junior Caicara and Omer Ali Sahiner for the starting spot, and Caicara's form in Europe may earn him a start here.
After beating Karagumruk, manager Osman Zeki Korkmaz made four changes to the side which eventually lost to Ankaragucu, with Melih Kabasakal, Ali Yasar, Emir Gultekin and Sidrit Guri perhaps unlucky to be dropped to the bench.
Some of those players may be drafted back into the starting lineup, but there will be no place for Eslem Ozturk who remains out injured, and Bosnian defender Denis Kovacevic may not be fit in time to play any part here, as he waits to make his debut following a summer transfer from Zeljeznicar.
Istanbul Basaksehir possible starting lineup:
Babacan; Caicara, Duarte, Ndayishimiye, Kaldirim; Tekdemir, Aleksic, Turuc; Traore, Okaka, Gurler
Istanbulspor possible starting lineup:
Jensen; Erdogan, Yesil, Mehremic; Berber, Rroca, Sarikaya, Aksu; Ethemi, Topalli, Guri
We say: Istanbul Basaksehir 2-1 Istanbulspor
Basaksehir are not showing the same sort of defensive strength they did at the start of the season, and Istanbulspor have players capable of unlocking their defence.