Key knocks by Jonny Bairstow and Rilee Rossouw helped Punjab Kings to a comfortable seven-wicket victory over defending champions Chennai Super Kings in the IPL yesterday.Chasing 163 for victory, Punjab depended on Bairstow’s 46 and 43 by Rossouw to achieve victory with 13 balls to spare at Chennai’s M A Chidambaram Stadium.England’s Bairstow kept up his form from the previous match when he hit an unbeaten 108 as Punjab chased down a record IPL target of 262 against Kolkata Knight Riders at Eden Gardens.Bairstow and Rossouw, a left-handed South African batsman, put on 64 runs for the second wicket to set up the chase.Shivam Dube had Bairstow caught behind and Shardul Thakur bowled Rossouw to have Punjab in trouble at 113-3 in 12 overs. Shashank Singh, who made 25, and skipper Sam Curran, who hit 26, then put on an unbeaten stand of 50 to steer the team home for just their fourth win and keep their slim play-off hopes alive.Five-time winners Chennai have won five and lost five and stay fourth in the 10-team table led by Rajasthan Royals.The pitch in Chennai was not run-friendly as the hosts posted 162-7 riding on skipper Ruturaj Gaikwad’s 62 and late evening dew added to the home team’s misery. But bowlers set up victory with spinners Harpreet Brar and Rahul Chahar taking two wickets each in their miserly spells - both giving away 33 runs in eight overs combined.Gaikwad put on an opening stand of 64 with Ajinkya Rahane and despite losing wickets the other end kept calm to push the total forward. Gaikwad surpassed Royal Challengers Bengaluru star Virat Kohli (500) as the leading batsman in the T20 tournament with 509 runs in 10 innings. Gaikwad built key partnerships in the middle-order with Sameer Rizvi, who hit 21, and Moeen Ali, who made 15, before being bowled by left-arm quick Arshdeep Singh. Veteran M S Dhoni came out to a rousing reception from the home crowd in what is likely his last IPL as player and he hit 14 off 11 balls before being run out on the final ball.BRIEF SCORESPunjab Kings 163 for 3 (Bairstow 46, Rossouw 43) beat Chennai Super Kings 162 for 7 (Gaikwad 62, Rahane 29, Chahar 2-16, Brar 2-17) by 7 wickets.