Despite their age disparity, Bagtas, 46, blended well with Kim, 16, as they tamed the Riviera Golf and Country Clubs Couples Course with three birdies and one bogey for nines of 34 and 36.
"Maganda ang team-up namin ni Chung Hoi," said Bagtas. "We blended well as a team, which is a must in this kind of tournament."
Rookie pro Marlon Dizon and buddy Bones Floro came up with a 74 to share second place with Arnaldo Gomez and Peter Elardo in the event with the format of one ball, twosome.
Vince Lauron and amateur partner Paul Salvador scored a 75 to lead the next group together with Armando Eso and Amado Eso and Lito Rempojo and Kim Hyung Soo.
Noli Kempis and Erwin Vinluan, who won the revival of the Fort Bonifacio Pro-Am at the nearby Langer Course last year, stayed in contention after a 76.
Tied with the defending champions were Juanito Pagunsan and his young son Juvic, who had to settle for second last year after self-destructing in the final homestretch.
U-Bix Corporation, Konica, Caffe Appassionato, San Miguel Corporation, Pagcor, Mizuno, DHL, WWW Express and Philippine Sports Commission are the events sponsors.
Cash prizes totaling P800,000 and P200,000 are up for grabs in the pro and amateur divisions, respectively.
Bagtas and Kim, who calls Mimosa his home course, started hot when they birdied the par five second hole. Then Bagtas sank a 35-footer to make the turn with a two-under par 34.
They collected their third bird from seven feet to go three under after 10 holes but they missed the next green for bogey. They parred the next seven holes for a 36.
Former Uratex champion Ruel Banares and amateur partner Erik Escalona came up with a 77 to lead the next group. Tied with them at five over par are the tandems of Dan Cruz-Mikee Camitoc, Benjie Magada-Arnold Duay and Kenji Yamaoka-Marvin Dumandan.
Former national champion Angelo Que celebrated his pro debut with a 79 in partnership with Camp John Hay senior vice president for marketing Shean Bedi.