Samuels shrugged off recent allegations of passing vital team information to an Indian bookie on his side's last tour of the sub-continent to hit seven fours and two sixes before he retired on 100, as West Indies set Kenya 269 to win.
A handful of the Kenyan batsmen got starts, but no one was able to carry on, as the visitors were restricted to 247 for seven from their allocation of 50 overs.
Collins Obuya struck two fours in an unbeaten 54 to top score for Kenya, Ravindu Shah supported with 41, skipper Steve Tikolo made 34, and Tanmay Mishra got 22.
Kenya suffered a setback in the third over, when David Obuya was caught at first slip for seven off Daren Powell, who also had Maurice Ouma caught in the same position for nine in the 11th over to leave Kenya 40 for two.
Corey Collymore then bowled Malhar Patel for 12 in the 15th over before he deceived Shah with a slower ball and had him caught at mid-on.
Obuya put on 55 for the seventh wicket with Thomas Odoyo, who got 24, to beef up the Kenyan total.
Earlier, the Kenyans were unable to keep a cork on the West Indies' scoring, as Samuels exploded in the latter stages to boost West Indies to 268 for six from their 50 overs.
After Shivnarine Chanderpaul was caught at second slip off Thomas Odoyo for a duck in the third over, left-handers Chris Gayle and Devon Smith added 58 for the second wicket to give momentum to the West Indies' innings.
Smith was caught at mid-on for 14 off Rajesh Bhudiya in the 16th over to bring Samuels to the crease and the hometown boy scratched around during the initial period.
By this time, Gayle was in full cry and reached his half-century before gifting his wicket, when he tried to reverse sweep and was bowled for 75 off 90 balls which included nine fours and one six.
Samuels emerged from his uncertain start, and reached his 100, when he guided Lameck Onyango to third man for a single, and continued to retreat to the dressing room to allow teenager West Indies newcomer Kieron Pollard to come to the wicket.
India will feature in the second warm-up match at Trelawny on Tuesday, when they face lightweights the Netherlands.
West Indies, the World champions in 1975 and 1979, have been drawn with Pakistan, Ireland, and Zimbabwe in Group D of the tournament in Jamaica.
Kenya, surprising semifinalists in 2003, challenge England, New Zealand, and Canada in Group B to be contested in St. Lucia.
The 2007 World Cup officially opens on Sunday at the Trelawny Multi-Purpose Stadium.
West Indies 268 for six off 50 overs (Marlon Samuels 100 retired out, Chris Gayle 75, Ramnaresh Sarwan 27, Dwayne Smith 22 not out; Thomas Odoyo 2-30, Hiren Varaiya 2-53). Kenya 247 for seven off 50 overs (Collins Obuya 54, Ravindu Shah 41, Steve Tikolo 34, Thomas Odoyo 24, Tanmay Mishra 22; Daren Powell 2-23, Corey Collymore 2-42, Kieron Pollard 2-56).