Quinahan collected 21 points, nine rebounds, four blocks and two assists in a brave stand against the 6-foot-8 Ekwe, who amassed 18 points and 16 boards.
Getting tremendous boost from Quinahan, the Comets, coming off a 65-58 spanking of the Henkel-Sista Super Sealers, scored a second straight win and their third in four matches.
The Spinners slid to 1-3.
"He is proving to be a vital cog in this team," said Mail and More coach Lawrence Chongson of Quinahan, whom they picked from the dispersal draft last September.
The win could serve Mail and More in good stead as it tangles with Hapee Toothpaste-PCU on Saturday. The Teeth Sparklers remain the only unbeaten team in the field.
"It’s going to be another big test for us. We will know in that game if we’re really a contender or mere pretender," Chongson said.
Ekwe highlighted his showing with several jarring slams, but Quinahan stole the thunder in the end.
Quinahan made 10 points in the third quarter, fuelling a decisive Mail and More breakaway.
Toyota Otis outmaneuvered Harbour Centre at the finish, carving out a 64-60 decision in the second game.
The Sparks drew even with the Portmasters, the CL Pera Padala Moneymen and TeleTech Titans on their identical 2-2 records.