Primera División de México Apertura 2003
Primera División de México ' Apertura 2003''' is a Mexican football tournament - one of two short tournaments that take up the entire year to determine the champion of Mexican football. It began on Saturday 2 August 2003, and ran until 22 November, when the regular season ended. Irapuato was promoted to the Primera División de México to play this tournament, and Cuernavaca was to be relegated to the Primera División A. The Cuernavaca did not get to play in Primera A, though, as the team was disbanded by FMF. On 20 December, Pachuca defeated Tigres UANL and became champions for the third time.
Overview
- Necaxa moved from Mexico City to Aguascalientes.
| Team | City | Stadium | - |
| América | Mexico City | Azteca | - |
| Atlante | Ciudad Nezahualcóyotl, State of Mexico | Neza 86 | - |
| Atlas | Guadalajara, Jalisco | Jalisco | - |
| Chiapas | Tuxtla Gutiérrez, Chiapas | Víctor Manuel Reyna | - |
| Cruz Azul | Mexico City | Azul | - |
| Guadalajara | Guadalajara, Jalisco | Jalisco | - |
| Irapuato | Irapuato, Guanajuato | Sergio León Chávez | - |
| Morelia | Morelia, Michoacán | Morelos | - |
| Monterrey | Monterrey, Nuevo León | Tecnológico | - |
| Necaxa | Aguascalientes, Aguascalientes | Victoria | - |
| Pachuca | Pachuca, Hidalgo | Hidalgo | - |
| Puebla | Puebla, Puebla | Cuauhtémoc | - |
| Querétaro | Querétaro, Querétaro | Corregidora | - |
| San Luis | San Luis Potosí, S.L.P. | Alfonso Lastras | - |
| Santos Laguna | Torreón, Coahuila | Corona | - |
| Toluca | Toluca, State of Mexico | Nemesio Díez | - |
| UAG | Zapopan, Jalisco | Tres de Marzo | - |
| UANL | San Nicolás de los Garza, Nuevo León | Universitario | - |
| UNAM | Mexico City | Olímpico Universitario | - |
| Veracruz | Veracruz, Veracruz | Luis "Pirata" Fuente |
Final standings (groups)
League table
Results
Top goalscorers
Players sorted first by goals scored, then by last name. Only regular season goals listed.| Rank | Player | Club | Goals |
| 1 |  Luis Gabriel Rey | Atlante | 15 |
| 2 |  José Cardozo | Toluca | 13 |
| 3 |  Carlos María Morales | Atlas | 12 |
| 3 |  Reinaldo Navia | Morelia | 12 |
| 5 |  Alex Fernandes | Monterrey | 11 |
| 5 |  Emilio Mora | Veracruz | 11 |
| 6 | Jared Borgetti | Santos Laguna | 10 |
| 6 | Eliomar Marcón | UAG | 10 |
| 6 |  Alfredo Moreno | Necaxa | 10 |
| 9 | Cuauhtémoc Blanco | América | 9 |
| 9 | Walter Gaitán | UANL | 9 |
| 9 | Luis Ignacio Quinteros | Puebla | 9 |
| 9 | Andrés Silvera | UANL | 9 |
Source:
Playoffs
Repechage
Toluca won 6–4 on aggregate.----
Cruz Azul won 4–1 on aggregate.
Bracket
Quarterfinals
2–2 on aggregate. UANL advanced for being the higher seeded team.----
Toluca won 4–2 on aggregate.
----
Pachuca won 4–3 on aggregate.
----
Atlante won 5–3 on aggregate.
Semifinals
UANL won 2–1 on aggregate.----
Pachuca won 2–1 on aggregate.