Group A, Cape Town: India 311-2 (50 overs) beat Namibia 130 all out (42.3 overs) by 181 runs
Sachin Tendulkar and Sourav Ganguly both scored centuries to guide India to an easy 181-run victory against Namibia.
Tendulkar hit 18 boundaries in his 152 from 151 balls to equal Mark Waugh's record of four World Cup tons.
He put on 244 for the second wicket with his captain, who hammered four sixes and six fours in an unbeaten 112, as India finished on 311-2.
Namibia's batsmen, by contrast, looked all at sea against the swing of Zaheer Khan and the spin of Harbhajan Singh as they crumbled to 130 all out.
India were asked to bat first and lost Virender Sehwag early on to Rudi van Vuuren.
Sehwag, who was promoted to opener, struck boundaries off successive balls before pulling the next delivery straight to Danie Keulder at midwicket.
Tendulkar was then dropped on 32 as he cut Louis Burger straight to brother Jan-Berry Burger at gully.
With Namibia bowling with discipline early on, the batsmen were happy to build their partnership slowly, before cutting loose in the last 10 overs.
Sachin Tendulkar (Ind): 34
Sourav Ganguly (Ind): 20
Saeed Anwar (Pak): 19
Mark Waugh (Aus): 18
Desmond Haynes (WI): 17
Tendulkar reached his second-highest one-day score with a brace of fours off van Vuuren but was then clean bowled attempting a heave in the same over.
Ganguly brought up his 50 with a huge straight six.
He was inconvenienced just once in his innings when he was struck on the chin by Burton van Rooi just after reaching his 20th one-day ton.
Indian seam bowler Ashish Nehra could only bowl two balls after slipping and twisting his ankle in delivery stride.
Zaheer Khan came on to complete his over and soon trapped Stefan Swanepoel and Louis Burger lbw with perfect swinging yorkers.
Dinesh Mongia took a brilliant diving catch on the boundary to dismiss Keulder off the bowling of Harbhajan.
Mongia followed up by bowling Jan-Berry Burger, who struck a six and four fours in his 29.
Namibian captain Deon Kotze put on 51 with Melt van Schoor before chipping a simple return catch to Mongia for 27.
Yuvraj Singh picked up four late wickets and Javagal Srinath swooped to recover Harbhajan's fumbled catch to dismiss Gerrie Snyman and wrap up Namibia's innings.
India: Sachin Tendulkar, Virender Sehwag, Sourav Ganguly
(captain), Rahul Dravid, Yuvraj Singh, Mohammad Kaif, Dinesh
Mongia, Harbhajan Singh, Javagal Srinath, Zaheer Khan, Ashish
Namibia: Stefan Swanepoel, Jan-Berry Burger, Danie Keulder,
Gavin Murgatroyd, Louis Burger, Deon Kotze (captain), Melt van
Schoor, Gerrie Snyman, Bjorn Kotze, Rudi van Vuuren, Burton van
Umpires: Aleem Dar and D R Shepherd.