In just 27 balls, the pair brought up the 50-run partnership before Rana got the back of the duo in successive balls.
De Villiers (44, 23b, 1x4, 5x6), judging every ball to perfection until that moment, top-edged a pull to mid-wicket. But just when the visitors were looking steady with McCullum looking in fine touch and Kohli at ease playing second fiddle, Sunil Narine (1/30) got rid of the unsafe Kiwi with a shortish offbreak that dislodged the stumps.
RCB chased 176 runs in 20 overs by losing 7 wickets and set a target of 177 runs in front of its opponent Kolkata Knight Riders. Narine's 19-ball 50 (he raised the half-century off 17 balls) laid the impetus that KKR so almost lost in the middle overs into their chase of 177.
"The batting has been strong point for RCB over the years, but I think the strengthening of bowling department has been a massive boost for us from this auction".
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Danny Welbeck looked keen to add to his tally, but he missed an open goal initially. Other teams in the league are more clinical.
He lost his partner, Chris Lynn (five) in the same over but he remained unperturbed and went berserk in the fourth over of Chris Woakes who was hammered for 6-4-4-6.
Narine's dominance continued in the next over with the young Washington Sundar at the receiving end.
McCullum had entertained his fans with six fours and four sixes. De Villiers mistimed Rana and Mitchell Johnson took the catch between long on and deep mid wicket. The bowling attack still does not inspire much confidence though, with massive responsibility on the shoulders of Chris Woakes and Yuzvendra Chahal. The Vidarbha pacer scalped Robin Uthappa in his next over to reduce KKR to 83/3 in the seventh over. But the duo of Dinesh Karthik and Nitish Rana calmed the nerves and made sure there was no collapse in the pursuit of their chase. Kohli was dismissed on the very next ball as he struggled to face the spinner.
Kolkata: Chris Lynn, Sunil Narine, Andre Russell and Mitchell Johnson are the four overseas players.
However, Rana's special show denied RCB a huge total. Courtesy of his fantastic all-around effort the Trinidadian was awarded as the Player of the match.