Warnapura retired out on 132 and Jayawardene was dismissed for 99, as the visiting Sri Lankans reached 343 for five when stumps were drawn on the opening day of their three-day, non-first class, tour match at the Guyana National Stadium.
Warnapura struck 14 fours and one six from 184 balls in just over four hours and shared in significant partnerships with opener Michael Vandort, who scored 29, and Jayawardene, whose knock contained a dozen boundaries from 110 balls in just over two hours.
No GCB President's Select XI bowler distinguished themselves, as they were made to toil in sweltering heat, after allowing the visitors to bat first.
GCB President's Select XI captain Patrick Browne is the most experienced player in his side, since choices for the composite West Indies side were restricted by the involvement of more established players in the sixth round of the West Indies first-class championship which ended on Monday.
As a result, Kemar Roach, playing his first full season of first-class cricket for his native Barbados, and uncapped, teenaged, fellow fast bowler Jason Dawes, a Jamaican member of the West Indies Under-19 side that won the Plate Championship of the ICC Youth World Cup in Malaysia, were the new-ball bowlers.
This failed to dampen the desire of the Sri Lankans for solid batting to send a strong message to their opponents for the upcoming Test and One-day International series, and Warnapura and Jayawardene made sure they achieved this objective.
Warnapura added 115 for the first wicket with Michael Vandort, but they were both fortunate to have survived until lunch, when Sri Lanka had reached 102 without loss.
After the interval, Sri Lanka lost Vandort to leg-spin bowler Davendra Bishoo when he was bowled for 29.
Kumar Sangakkara came to the crease and added 59 for the second wicket before leg-spin bowler Shamarh Brooks, the West Indies Under-19 captain at the Youth World Cup, bowled him behind his back for 22.
Jayawardene joined Warnapura and fortune also favoured him, when Roach dropped him on six on the mid-wicket boundary off Steve Jacobs, the West Under-19 vice-captain at the Youth World Cup.
The Sri Lanka captain continued to play as languidly as he always does and reached his 50 minutes ahead of tea, but not before Warnapura reached his hundred.
At tea, Sri Lanka were 253 for two, and Warnapura retired his innings during the break to allow Thilan Samaraweera to join Jayawardene.
They continued to dominate the bowling and put 68 for the third wicket before Jacobs bowled Jayawardene and Samaraweera was run out just before the close.
The first Test between West Indies and Sri Lanka will contested from March 22 at this same venue, and the second Test will be from April 3 at Queen's Park Oval in Trinidad.
The first two One-day Internationals will be on April 10 and 12 at Queen's Park Oval, and the third ODI will be a day/night affair at the Beausejour Stadium in St. Lucia on April 15.