Andrew Symonds returned to form with a half-century, while Vaas picked up three wickets.
Chennai: Veteran Sri Lankan pacer Chaminda Vaas starred with the ball as defending champions Deccan Chargers returned to winning ways by brushing aside Chennai Super Kings by 31 runs at the M A Chidambaram Stadium on Sunday.
Vaas took three wickets in his first two overs - Murali Vijay, Suresh Raina and Matthew Hayden - as Chennai, chasing a stiff 191 for victory, lost too many wickets at the start. Captain MS Dhoni (42) and Albie Morkel (42 not out) provided some late fireworks but Chennai could only manage 151 for the loss of nine wickets.
Chennai made a disastrous start to their run chase when Murali Vijay and Raina fell in the same over to Vaas. Hayden looked in fine touch but an adventurous shot to clear the short fine leg ended his stay.
The introduction of Pragyan Ojha into the attack brought immediate results as S Badrinath and Justin Kemp fell to the left-arm spinner, and by the time Dhoni and Morkel got together, Chennai had too much to ask for from the pair.
Dhoni's entertaining 42 lasted 29 balls and included two sixes before Andrew Symonds bowled the Chennai skipper. Morkel kept the fight alive with a barrage of sixes but the hosts ran out of overs.
Earlier, Andrew Symonds returned to form with a half-century while Herschelle Gibbs scored a fine 45 to lift Deccan Chargers to 190-4.
Symonds cracked three sixes in his 43-ball knock while Gibbs struck five fours and a six as the duo added 95 runs for the third wicket, after captain Adam Gilchrist got the Chargers off to a lightning start after electing to bat.
Gilchrist reached 1000 runs in IPL games in his brutal 17-ball 38 but two quick wickets - that of Gilchrist and VVS Laxman - pegged the defending champions back.
Gibbs and Symonds steadied the Chargers before launching into the Super Kings, but the visitors were again pulled back by the run outs of both the batsmen. Rohit Sharma and Tirumalasetti Suman then lifted the team to a stiff total in the final overs.
Off-spinner R Ashwin was the most successful bowler for Chennai with 1-26 from his four overs, while star spinner Muttiah Muralitharan gave away 28 runs from his four.