Shane Watson slammed a stroke-filled century and was also involved in an 80-run opening stand with Ajinkya Rahane (37; 22b, 3x4s, 2x6s) as Rajasthan Royals beat Kolkata Knight Riders by 9 runs in the 'virtual quarterfinal' at the Brabourne Stadium on Saturday. Pacer Chris Morris too chipped in with four wickets as Rajasthan Royals qualified for the Playoffs, leaving KKR on the brink of elimination. Watson's 59-ball 104, which included five mighty sixes and nine fours, ensured the Royals posted a formidable 199-6 in 20 overs at their 'second home' after they won the toss and elected to bat. Kolkata put up a brave reply , with Yusuf Pathan (44) and Andre Russell (37) doing the bulk of the work, but they managed only 190. Royals, the 2008 champions also benefited from KKR skipper Gautam Gambhir's decision to drop their spin mainstay Sunil Narine in the crucial tie. Narine was replaced by Pakistan all-rounder Azhar Mahmood (3-0-41-0), who failed to make an impact in his first appearance of the season.