In June 1983, he joined elder brother Danny in the power-laden Mama's Love basketball club team.

It was there where he got his biggest break and exposure, his reentry in the Manila basketball scene via the premier amateur league (PABL).

In a short span of time, Lastimosa won MVP honors while playing for Mama's Love in the first conference of the 1985 PABL season.

[1] The following year, he became teammates with Samboy Lim and they led the Lhuillier Jewelers to the championship of the PABL's first conference.

He spent his last two years in the amateur league with the Jewelers of coach Yayoy Alcoseba although he was a borrowed player when RFM-Swifts won their first PABL title in the 1987 International Invitational Cup and was voted Most Outstanding Player of the tournament, besting former national teammate Alvin Patrimonio.

Lastimosa, along with Jerry Codiñera, were the two early entries to the pro league signed by newcomer Purefoods Hotdogs.

[6] Lastimosa served as an assistant coach of the Aces under Tim Cone,[7] Joel Banal and Luigi Trillo.

[14] Lastimosa played for the Philippine national basketball team for two occasions of Asian Games, first in 1986 as an amateur player, and in 1998 as a professional.