Kolkata (PTI): Yusuf Pathan and Mohammad Kaif drummed up a crucial unfinished 81-run partnership as Rajasthan Royals confirmed their semi-final berth by cantering to a six-wicket victory over a lacklustre Kolkata Knight Riders here on Tuesday.

Pathan (48 not out off 18 balls) and Kaif (34 not out off 31 balls) took the game away from the Knight Riders during their rollicking 42-ball stand after the hosts posted a modest 147 for eight in the face of a disciplined bowling performance from the league leaders.

Pathan, who played a hurricane knock studded with five fours and three sixes, ended the game in style with an overboundary off pacer Umar Gul as the Royals reached 150 for four with 21 (RPT 21) balls still remaining in the Eden Gardens game.

The Royals, now on 18 points from 11 outings, registered their ninth win of the tourney, while the Knight Riders' hopes to make the last four dimmed further with the defeat. The Sourav Ganguly-led side remained on 10 points after 12 ties.

Set an easy asking rate of 7.4, the Royals lost the young Swapnil Asnodkar (5) early before South African Graeme Smith and Sohail Tanvir came together in the middle to pull their team out of trouble.

The two came down hard on Ajit Agarkar in the fifth over, plundering 16 runs, with Tanvir hitting a four and a six to a boundary picked up by Smith as the visitors seemed comfortably placed at 42 for one after five overs.

Ganguly turned to pacer Umar Gul, who replaced injured Shoaib Akhtar in the side, and the Pakistani pacer immediately gave a dramatic twist to the game by seeing the back of both the batsmen in the next over.