Two-time champions ATK made their Christmas celebrations special, pipping Bengaluru FC by a David Williams solitary strike to secure their first ever win over the defending champions in the Indian Super League, in Kolkata, on Wednesday.
On a day the Sunil Chhetri-led side had better ball possession, Williams scored the winning goal with an explosive finish in the 47th minute after being set up by their captain Roy Krishna.
The Fijian's pass was so clear that Rahul Bheke failed to clear it away and lost the possession to Jayesh Rane who slided it to the surging Williams. The Australian forward made a couple of touches before an explosive finish at the far post, giving a diving Gurpreet Singh Sandhu no chance.
This was ATK's first ever win over Bengaluru FC from five attempts and it could not have come on a better day as the Antonio Habas side climbed to the top of the table, ahead of FC Goa on goal difference, both having 18 points each.
There was little to differentiate between the two teams as Bengaluru FC had 58 per cent ball possession at the goal-less halftime.
Michael Soosairaj was exceptional for the home team but the final touch was missing as they played some smooth passing games and were unlucky not to go ahead.
Bengaluru FC forward line failed to penetrate the opposition citadel in a thrilling first 45 minutes.
The win also meant that ATK remained the only team to be unbeaten at home, while this was the first loss away from home for the Carles Cuadrat's Bengaluru FC this season.
The Blues had the chance to equalise on the hour mark when Harmanjot Khabra's cross in the ATK box came off the head of a red shirt and fell kindly to Dimas Delgado.
But the Spanish midfielder, under no pressure, fired agonisingly wide on the volley. Cuadrat soon made his first change, introducing Ashique Kuruniyan for Bheke, as Bengaluru switched shape, going with four at the back.
With the home side continuing to keep things tight at the back, Bengaluru made a second attacking change by bringing on striker Semboi Haokip for Augusto.
Udanta and Ashique attacked the flanks with Semboi the focal point, but the Blues could do little against a resolute ATK defence that held fort to secure the full three points.