Phil Salt's attacking 68 and bowling figures of 3-16 by Varun Chakravarthy helped Kolkata Knight Riders hammer Delhi Capitals by seven wickets at a hot and humid Eden Gardens in the IPL on Monday.

Chakravarthy, a mystery spinner, led Kolkata's disciplined bowling to restrict Delhi to 153-9 as players, who remained drenched in sweat, and fans braved the intense heat in the colonial-era capital.

Players from all the 10 IPL teams are keen to impress their national selectors with just one day left for countries to name their teams for the T20 World Cup in June.

The in-form Salt, an England wicketkeeper-batsman, led the chase with an opening stand of 79 with Sunil Narine and the two-time champions reached their target with 3.3 overs to spare.

The mercury in the afternoon soared above 41 degrees Celsius (106 degrees Fahrenheit) for the third time this month, forcing the normally bustling streets to stay empty at noon.

But the sports-mad city witnessed a near-packed house at the 66,000 capacity stadium for the evening game and their home team did not disappoint with their sixth win in nine matches to move closer to booking a play-off spot.

Most of India's eastern states and southern peninsula have remained under government heatwave alerts since last week, with relief not expected for several more days.

Delhi elected to bat first but lost regular wickets including Prithvi Shaw for 13 and fellow opener Jake Fraser-McGurk, out for 12 off let-arm quick Mitchell Starc.

Skipper Rishabh Pant attempted to resist the slide in his unconvincing knock of 27 before he was dismissed.

Chakravarthy rattled the middle and lower-order to make Delhi slip to 111-8 before number nine Kuldeep Yadav claimed an unbeaten 35.

Salt, who moved into the top five batsmen this IPL season with 392 runs, put the chase on track along with fellow opener Narine as the two clobbered 23 runs off the first over from Lizaad Williams.

He reached his fourth half-century of the season in 26 balls with a six off Khaleel Ahmed but fell to spinner Axar Patel after his 33-ball knock laced with seven fours and five sixes.

Skipper Shreyas Iyer, who made 33, and Venkatesh Iyer, who hit the winning six in his 23, steered the team home in an unbeaten stand of 57.

The match was a complete contrast to the previous game at the venue when Punjab Kings chased down an IPL record of 262 on another hot day.