Bangalore, Oct 6 (IANS): In a nail-biting finish, Royal Challengers Bangalore (RCB) late Wednesday snatched a thrilling victory by two wickets from a defiant South Australian Redbacks (SAR) to qualify for semi-finals of the ICC Champions League Twenty20 (CLT20) at the Chinnaswamy stadium here.

Requiring six runs of the last ball in the 20th over for a sensational win, RCB's wicket-keeper Arun Karthik lofted a massive six of Redback's Daniel Christian to reach the stiff target of 215 for eight wickets.

Though RCB's swashbuckling openers Chris Gayle (26) and Tillakaratne Dilshan (74) began the hot chase to rustle up 65 in first six overs, a brilliant century partnership for the second wicket in 54 balls between Dilshan and Virat Kohli (70) took the home team closer to the target.

In a fearsome bowling spell, speedster Shaun Tait, however, ran through Dilshan, skipper Daniel Vettori and Raajoo Bhatkal in the 19th over to swing the match towards Redbacks and reduced RCB to 200 for 7, requiring 15 of the last over.

After Syed Mohammad was run out for two on the second ball of the last over, it was left to Karthik and left-arm pacer Sreenath Arvind to make the remaining 13 from four balls.

A quick four and a single by Arvind with two wides by Christian reduced the target by six runs of the last ball for Kartik to hit the winning six.

Kohli was declared Player of the Match for his quick fire 70 in 36 balls with six huge sixes and four fours.

For Redbacks, Tait was the most successful bowler with five wickets in four overs for 32 runs.

With two wins from four matches, Group B runners-up RCB will play against Group A topper New South Wales (NSW) here Friday in the first semi-final, while Group B topper Somerset will play against Group A runners-up Mumbai Indians in Chennai Saturday for the tournament's title clash in Chennai Sunday.

Earlier, winning the toss and opting to bat, Redbacks scored a blisterring 214 for two wickets in 20 overs, with opener Daniel Harris remaining unbeaten on 108 with 17 fours and two sixes in 61 balls.

With Callum Ferguson, who hit a breezy 70 in 43 balls by blasting three sixes and four fours, Harris put up a 114-run partnership for the second wicket.

Redbacks also blasted RCB bowlers to hit 86 in the last five slog overs.

For RCB, Syed Mohammed and Raajoo Bhatkal struggled to share one wicket each.