David started out as an intramural player at the Lyceum of the Philippines University, the same school he later powered to three runner-up finishes in the NCRAA versus a star-studded St. Francis of Assisi team led by behemoth brothers Yancy and Ranidel de Ocampo.

David brought high energy to Air21's running game and was a major factor of the Express securing the third-place finish in that season's Fiesta conference.

David exploded for 19 points to carry the Express to its first-ever Final Four appearance after upsetting the Darvin Ham-led Talk 'N Text Phone Pals, 117–110, in Game 5 of the quarterfinals on January 20, 2006 in Antipolo City.

Throughout the course of the season, David improved his numbers significantly by averaging 21.3 points per game with 4.1 rebounds and 2.4 assists to go as he took the role of being the team's main man.

Prior to an unfortunate elbow injury, David was having an impressive season and was on the verge of a probable MVP award, only losing in the voting process to eventual winner Willie Miller.

Despite several injuries in the past, David took the cudgels as the team's go-to-guy after former franchise player Renren Ritualo was shipped to Talk 'N Text and the energetic Ronald Tubid to Ginebra.

During the middle of the conference, however, David regained his starting spot and minutes and quickly became the team's go-to-guy along with Arwind Santos.

During the Fiesta Conference, the newly named Burger King Whoppers finished at the number 4 spot and earned a twice-to-beat advantage entering the wildcard phase.

[5] But shortly after Japeth's PBA Debut, he was then traded to the Talk 'N Text Tropang Texters for him to be able to play for the Smart Gilas Pilipinas National Team.

They faced David's former team Burger King Whoppers in the first round of the wildcard and beat 118-112 but were eventually eliminated by the Rain or Shine Elasto Painters after losing, 84-99.

The Tigers started out the conference winning four of their first five assignments but shortly after, they suffered a 6-game losing streak that affected their bid for the automatic quarterfinal berth.

Despite being the league's leading scorer, a poor finish by the team caused David to lose the Best Player of the Conference Award to San Miguel Beermen's Jay Washington.

Despite being tied with Rain or Shine and B-Meg after compiling a 4–4 record, Powerade did not make the playoffs as the quotient system did not favor them.

In the 2011–12 PBA Philippine Cup, David led his team to 6 wins and 8 losses during eliminations, as Powerade finished 8th to begin the playoffs.

Despite the Tropang Texters beating Powerade in 5 games to become back-to-back Philippine Cup champions, David's sterling performance is still regarded as one of the best in PBA playoff/finals history.

David was named the Best Player of the Conference for the PBA Philippine Cup, beating Petron Blaze Boosters' Arwind Santos, despite the latter leading in statistical points.

Powerade top official JB Baylon has confirmed that they are giving David the maximum monthly pay of P420,000—allowed under the league's amended salary cap rule.

[14] On October 11, 2013, David was traded to the Meralco Bolts with AJ Mandani in exchange for Chris Ross, Chris Timberlake and Meralco's 2016 and 2017 second round picks[15] He made his debut in a Bolts' uniform on November 17 in a losing effort against the Talk 'N Text Tropang Texters, 80-89, scoring 26 points and grabbing 7 rebounds.

[16] On March 13, 2016, David was penalized by the management of Meralco Bolts due to "insubordination, lack of dedication to the team; and breach of contract which states that he's obligated to play in official PBA games at all times" during a game against NLEX Road Warriors in the 2016 PBA Commissioner's Cup, according to the One Meralco Sports' website.

[25] [26][27] After winning the MVP plum in 2003 in the PBL, David was chosen to be part of the Philippine team that would compete in the 2003 Southeast Asian Games, starring alongside college rival Ranidel De Ocampo, University of the East star James Yap, Ateneo de Manila's Rich Alvarez, and PSBA's Marc Pingris.

David bailed out the Nationals, who squandered a 14-point lead before trailing by 12, with two clutch baskets in a row to propel the Philippines to a 3-0 start.

[35] He then led the Nationals along with LA Tenorio, to win the gold medal in the 2012 Jones Cup after beating the USA select team, 76-75.

[36] It was the country's first championship in the Asian level since the Philippine Centennial Team anchored by coach Tim Cone ruled the 1998 edition of the Jones Cup.