Out of the 46 entries under squad I, Tiu, who is carrying the name of BTA and Prima, toppled a total of 1,715 pins in eight games.
Tiu was able to recover right away after a slow start with only 156 pins as against teammate Edwin Apawan, who posted 220 in game 1.
Tiu made an average of 214.38 and leads by 35 pins over CETBA-Prima's John Gasataya.
Three other CETBA entries occupied the next three seats namely, Nestor Ponteres and Mario So at third and fourth spots with an identical 1,670 pinfalls and Nestor Longcanaya at fifth place with 1,666.
Edwin Apawan, for his part, failed to hang on and dropped to sixth spot with 1,653 pinfalls as teammate Edmund San Jose came in seventh with 1,628 pinfalls as CETBA's Joey Barbas settled eighth with 1,625 pinfalls.
BTA-Prima's Germaine Uang occupied the ninth place after dropping 1,616 pins as teammate, Luther Tapaya ended 10th with 1,610.
But more to it, Uang came to be the only female bowler to land into the top 10 cast out of the eight female entries.
Squad I was scheduled to finish the rest of the games last night while squad II starts their game tonight with 68 registered bowlers.
The week-long National event features bowlers coming from 13 associations all over the country.