Cornwall troubled the Trinidadian batsmen with a clever combination of subtle and prodigious movement off the seam to finish with five for 27 from 18 overs of deceptive medium pace.
They were eventually bowled out for 176 after being asked to take first strike by Leewards captain Steve Liburd. Elsroy Powell supported with three for 44 while off-spinner Omari Banks chipped in with two for 46.
At the close of play, Leewards were 30 for the loss of Mali Richards (2), 146 runs away from securing first innings points and with nine wickets in hand. Kieran Powell (11) and Montcin Hodge (10) were at the crease.
The 36-year-old Cornwall, playing in his first game of the season, opened the bowling with Lionel Baker and made immediate inroads when he bowled recalled opener William Perkins for a duck.
Shortly afterward, he dislodged the other opener – Justin Guillen for seven – via the lbw route to leave the Trinidadians on 17 for two which became 63 for five at lunch.
Leg-spinning all rounder Imran Khan proved his batting pedigree, top scoring with 53 while captain Daren Ganga made 51.
The pair moved the score from the lunch time position to 124, before Cornwall returned to bowl Ganga as he shouldered arms to a delivery which nipped back sharply from outside off stump.
Ganga faced 155 deliveries, six of which he hit for boundaries, but Khan was more aggressive during his first half century of the season which required 113 balls and included five fours and a six.
The pair resurrected the Trinidadian innings in the post-lunch session during which just one wicket fell but after the tea interval the innings was brought to a hasty conclusion with Cornwall formalizing his five-wicket haul when he had Richard Kelly (19) caught at the wicket by stand-in wicketkeeper Liburd.
The captain was forced to don the gloves after first choice keeper, Devon Thomas injured his left leg during fielding drills shortly before the toss.
With 13 tricky overs to negotiate before the close, the Leewards lost the son of Sir Viv Richards for two when Mali drove loosely at a delivery from debutant fast bowler Shannon Gabriel and was impressively caught low down at second slip by Jason Mohammed.
There were no further alarms as Hodge and Powell – who both made double ducks in their previous game against Jamaica – saw the Leewards to safety.
Both teams made a slew of changes, mainly owing to the departure of the West Indies players. Leeward Islands lost leading batsman Runako Morton and fast bowler Gavin Tonge and they dropped out-of form all rounder Tonito Willett.
The duo were replaced by Codville Rodgers and Elsroy Powell while Richards was brought in at the top of the order for Kieran Powell. Powell though retained his place after Thomas sustained the debilitating leg injury.
Trinidad and Tobago entered the game missing the tournament’s highest run scorers in wicketkeeper Denesh Ramdin, opener Lendl Simmons and pacer Ravi Rampaul.
They dropped Rayad Emrit from the squad while left-arm spinner Dave Mohammed lost his place in the playing XI. Perkins, wicketkeeper Gibran Mohammed, all-rounder Richard Kelly, spinner Sunil Narine and Gabriel were included.
SCOREBOARD
T&T 1st Innings
J Guillen lbw b Cornwall 7
W Perkins b Cornwall 0
*D Ganga b Cornwall 51
J Mohammed c Athanaze b Banks 5
S Ganga c Baker b Martin 12
+G Mohammed c Athanaze b Banks 2
I Khan c Banks b Cornwall 53
R Kelly c wkp Liburd b Cornwall 19
S Narine c & b Martin 2
A Jaggernauth not out 14
S Gabriel lbw b Martin 0
Extras (b2, nb9) 11
TOTAL (all out, 75 overs) 176
Fall of wickets: 1-0, 2-17, 3-31, 4-52, 5-63, 6-124, 7-155, 8-159, 9-171, 10-176.
Bowling: Baker 13-3-24-0 (nb1), Cornwall 18-7-27-5 (nb5), E Powell 7-1-21-0 (nb3), Banks 14-4-46-2, Martin 18-4-44-3, Athanaze 5-2-12-0.
LEEWARD ISLANDS 1st Innings
M Hodge not out 10
M Richards c J Mohammed b Gabriel 2
K Powell not out 11
Extras (lb4, nb3) 7
TOTAL (1 wkt, 13 overs) 30
Fall of wicket: 1-7.
To bat: *+S Liburd, C Rogers, O Banks, W Cornwall, E Powell, J Athanaze, L Baker, A Martin.
Bowling: Kelly 5-2-7-0 (nb2), Gabriel 5-1-15-1, Khan 2-0-4-0 (nb1), Jaggernauth 1-1-0-0.
Position: Leewards trail by 146 runs with nine wickets in tact.
Toss: Leewards.
Umpires: G Greaves & R Brathwaite.