Kolkata, Dec 5 : Mohun Bagan defeated Kalighat Club by six wickets in a must-win game to keep their chances alive to make the knockouts of the Bengal T20 Challenge thanks to Vivek Singh's blistering 24-ball 61 and Writtick Chatterjee's all-round brilliance at the Eden Gardens here on Saturday. With this crucial victory, Bagan climbed up to third position with 16 points from 9 games, while Kalighat are at fourth with same points. Electing to bat first, Kalighat posted 150/6 in their quota of 20 overs as Prinan Dutta continued his good form with 40 off 33 balls while Toufik Mondal smashed a quickfire 21-ball 33. For Bagan, Writtick and Akash Deep bagged 2 wickets apiece. While chasing, Bagan lost opener Ankur Pal in the very first over but Vivek and Writtick stitched a 87-run partnership to lay the foundation for a comfortable victory. Vivek came out all guns blazing to smash 3 sixes and 10 boundaries enroute his fifty, while Writtick made 43 off 31 deliveries. An elated Vivek said: "We knew it was scoring wicket and our plan was to use the powerplay well. This would make the job easier for the latter batsmen. The partnership between me and Writtick was good and that made the chase more comfortable." Bagan skipper Anustup Majumder stayed unbeaten on 18 to help Bagan cross the line in 15.5 overs. /IANS