Mumbai, May 17 (IANS): A blistering century by opener Shane Watson and some quality bowling helped Rajasthan Royals secure a place in the Indian Premier league play-offs with a nine-run victory here on Saturday over defending champions Kolkata Knight Riders whose chances now seem very slim.

Watson rose up to the occasion in the Royals' must-win match to remain unbeaten at 104 off 59 balls, plundering nine fours and five sixes to help the home side post a challenging 199/6. In reply, Kolkata fought till the end but fell short of the target, managing 190/9 in 20 overs.

With the win, Rajasthan entered the IPL 2015 play-offs climbing from the sixth to the second spot with 16 points from 14 games.

Kolkata's chances of making it to the play-offs look very tough as they have secured 15 points from 14 games. They are now placed fourth, but would be overtaken by the winner of the Sunrisers Hyderabad versus Mumbai Indians match. However, Knights could be in with a chance if the Hyderabad-Mumbai match is washed out. Another arithmatical possibility favouring the Knights could be if in the other Sunday outing, Delhi Daredevils inflict a very huge defeat on Royal Challenger Bangalore.

For Rajasthan, Chris Morris (4/23), Dhawal Kulkarni (2/36) and Watson (2/38) was the pick of bowlers.

Chasing 200 to win, Kolkata got off to a worst possible start losing both the openers skipper Gautam Gambhir (1) and Robin Uthappa (14) within three overs.

But Manish Pandey and Yusuf Pathan didn't let the asking rate go up, as they struck couple of boundaries and sneaked in with quick singles and twos to help the visitors reach 50 in the sixth over.

Pandey (21), looking to up the scoring rate, fell on the first ball of the 9th over, but Pathan and Andre Russell ensured Knights were on course to chase down the target.

The duo, with some explosive shots, brought team's 100 in 10.3 overs.

But bowling change by Royals worked wonders in the 14th over. Pacer Chris Morris got the better of hard-hiting Russell (37; 20b, 4x4, 2x6), and then saw the back of Suryakumar Yadav (0).

Kolkata were 133/5 in 13.4 overs then.

Pathan (44; 35b, 5x4, 1x6) who was striking it well also departed trying to up the scoring rate in the 16th over.

With his departure wickets fell at regular intervals thus making it difficult to chase.

Earlier, opting to bat first, Royals got off to a flying start with openers Ajinkya Rahane and Watson striking the ball at ease to all parts of the park to score 66 in the first six overs.

As Royals were merrily scoring runs, the seventh over saw Rahane (37; 22b, 3x4, 2x6) running himself out after a mix-up with his partner.

But the wicket didn't put the brakes on the scoring for Rajasthan as Watson kept on timing the ball sweetly to bring up his half-century in just 31 balls.

The Knights after getting hammered in the first 10 overs found luck when they got rid of Steve Smith (14), Sanju Samson (8) and James Faulkner (6) in quick succession in the space of four overs. Rajasthan were then 140/4 in 14.3 overs.

Karun Nair gave good support to Watson smacking three fours in his short innings of 16 off 9 balls till he departed in the 18th over.

For Kolkata, Andre Russell (3/32) was the pick of the bowlers.