Justifying skipper Gautam Gambhir's decision to field, Lakshmipathy Balaji (3-15) and his bowling colleagues shot out the visitors for 81 in 15.2 overs with Ashok Menaria (21) being Rajasthan's top scorer.
Unbeaten knocks by Gambhir (35) and Manoj Tiwary (30) helped Kolkata overwhelm the target in the 14th over and soar to the top of the table with six points from four matches.
Rajasthan Royals 81 in 15.2 overs (A. Menaria 21; L. Balaji 3-15, Shakib Al Hasan 2-21) lost to Kolkata Knight Riders 85-2 in 13.5 overs (G. Gambhir 35 not out, M. Tiwary 30 not out) by eight wickets.
Delhi Daredevils vs Pune Warriors
Mumbai: Yuvraj Singh's all-round brilliance was not enough in the end as Delhi Daredevils humbled Pune Warriors by three wickets for their maiden win in the Indian Premier League on Sunday.
Pune skipper Yuvraj, adjudged player of the tournament at the World Cup, hit five sixes in his unbeaten 66 off 32 balls that, along with Jesse Ryder's attacking 60, powered the home side to 187-5 at the DY Patil Stadium.
Returning to defend the total, Yuvraj claimed 4-29 but still could not stop Delhi, boosted by cameos from David Warner (46), Virender Sehwag (37) and Y Venugopal Rao (31), from reaching the target with four balls to spare.
Pune Warriors 187-5 in 20 overs (Yuvraj Singh 66 not out, J. Ryder 60, M. Manhas 20; S. Nadeem 2-39, A. Dinda 2-42) lost to Delhi Daredevils 190-7 in 19.2 overs (D. Warner 46, V. Sehwag 37, V. Rao 31, A. Finch 25; Yuvraj Singh 4-29) by three wickets.