[1] He is the current Pan American Games champion in Mixed Doubles winning the title in Santiago, Chile, with his sister Erika Manilla in 2023.

At the 2009 World Junior Championships in Santo Domingo, Dominican Republic, he and Zachary Wertz lost in the Boys U14 Doubles final to Mexicans Javier Estrada and Eduardo Garay, 12–15, 15–14, 11–9.

Manilla lost to Jose Diaz (Delta College), 12–15, 15–6, 11–2, in the semi-finals, then beat Joel Barshaw (Oregon State), 15–11, 15–14, in the 3rd place match.

[9] In doubles, Manilla and Nicholas Riffel lost in the final to Felipe Camacho and Brad Schopieray (Colorado State Pueblo), 12–15, 15–3, 11–0, after defeating Barshaw and Sam Reid in the semi-finals, 15–12, 15–12.

[11] At the 2014 IRF World Junior Championships in Cali, Colombia, Manilla lost in the quarterfinals of Boys U18 Singles to Bolivian Mario Mercado, 15–14, 5–15, 11–9.

[13] He also won doubles that year playing with Nicholas Riffel, and they beat Jacob Matthews and Brad Schopieray (Colorado State Pueblo), 15–8, 15–4.

[17] At the USA Racquetball Intercollegiate Championship in 2017 in Fountain Valley, California, Manilla lost in the semi-finals to Thomas Carter (Baldwin Wallace), 15–6, 13–15, 11–6, but won the 3rd place match against Mauro Rojas (Delta College), 15–12, 15–9.

[18] He and Nicholas Riffel also lost in the semi-finals of doubles, as Carter and Manolo Sandoval got the better of them, 15-12, 15-5, but they won the 3rd place match against Rojas and Francisco Troncoso, 15–14, 6–15, 11–6.

[31] At the 2020 USA Racquetball Doubles Championships in Tempe, Arizona, Manilla and Nicholas Riffel lost to David Horn and Eric Garcia in the quarterfinals, 7–15, 15–3, 11–5.

[38] Manilla's first IRT title came in doubles in September 2022, when he played with Jake Bredenbeck at the Capitol Classic in Severna Park, Maryland.

They defeated Javier Mar and Rodrigo Montoya in the quarterfinals, 9–15, 15–10, 11–1, then beat Samuel Murray and Andree Parrilla in the semi-finals, 15–11, 4–15, 11–3, and took out Andrés Acuña and Eduardo Portillo, 15-5, 15-11, in the final.

[40] In doubles, he played with Sebastian Fernandez, and they beat Mario Mercado and Mauricio Zelada in the Round of 16, 15-12, 15-6, but lost in the quarterfinals to eventual winners Alvaro Beltran and Daniel De La Rosa, 12–15, 15–4, 11–4.

[42] Manilla played doubles in Tempe with Wayne Antone, and they defeated Rocky Carson and Charlie Pratt, 13–11, 6–11, 9–11, 13–11, 11–8, in the semi-finals, but lost in the final to Daniel De La Rosa and Alejandro Landa, 15–13, 11–5, 11–8.

[43] Manilla won his second IRT doubles title with Andree Parrilla in March 2023 at the 38th Annual Shamrock Shootout in Lombard, Illinois.

[44] Manilla was runner up at the 2023 USA Racquetball National Singles Championship, as he lost to Daniel De La Rosa in the final, 3–11, 11–9, 11–8, 9–11, 11–6, after defeating Jake Bredenbeck in the semi-finals, 2–11, 11–8, 12–10, 11–2, and Thomas Carter in the quarterfinals, 9–11, 11–6, 14–12, 11-5.

[46] They won gold in Mixed Doubles in Santiago[47] by defeating the Independent Athletes team of Edwin Galicia and Gabriela Martinez in the quarterfinals,[48] then beat Mexicans Paola Longoria and Eduardo Portillo in the semi-finals.

[58] He was part of Team USA at the 2024 Racquetball World Championships in San Antonio, Texas, where Manilla played Men's Doubles with Sebastian Fernandez.