He started his career in Caribe Junior, where the Ecuadorian star played during his youth years. He showed his skills in the 2007 Pan American Games held in Brazil, where the Ecuadorian soccer team won the gold medal, and Martínez was a key player for the team. Independiente José Terán acquired his services and then sold him to Cruzeiro for an unknown fee.
After a move to Deportivo Quito, Martínez debuted on October 16, 2010 against El Nacional. He scored his only goal of the season against ESPOLI. He finished his debut season with 9 games, 1 goal and 1 assist.
Martínez played in 30 games in 2011, assisting 5 times and scoring 9 goals, one of which was in the first leg of the Serie A final against Emelec. Martínez scored his first goal of the 2011 season on May 14, against Quito club Espoli. He later scored 7 more league goals plus one vital finish past the Emelec goalkeeper. Thus winning the 2011 season.
2012 season
Martínez kicked of the 2012 season against Macara. On February 7, 2012 he played his first ever Copa Libertadores match against Chivas de Guadalajara. On March 7, he scored his first ever goal in the tournament against Velez Sarsfield in an emphatic 3-0 win over the Argentine team. On March 11, he scored his first league goal against Deportivo Cuenca in a 4-1 away win. On April 17, Martínez played a vital game against Mexican giant Chivas de Guadalajara in a historic 5-0 win in which he scored the third goal at the 65 minute mark. Martínez played all 6 games of the 2012 Copa Libertadores Group Stage, contributing two goals and two assists to help Deportivo Quito qualify to the Round of 16, an accomplishment not achieved since the 1989 Copa Libertadores. He scored his third Copa Libertadores goal in the Round of 16 against the powerful Chilean club Universidad de Chile in a 4-1 win.
On May 22, 2012 The president of Deportivo Quito Fernando Mantilla confirmed the purchase of Martinez by Tijuana for an undisclosed fee. Martinez made his professional debut with Xolos on July 20, coming on as a substitute in a 2-0 win over Puebla FC. Martínez scored his first goal in a Copa MX draw against Pumas, in a 2-2 away draw. On December 2, Martínez and Tijuana won their first ever first division league title, Martínez assisted both goals in Tijuana 2-0 away victory over Toluca. Martínez scored his goal of the year in a 4-0 Copa Libertadores match against San Jose of Bolivia, also assisting one goal. He later scored a late winner against Colombia's Millonarios at the last minute, and against Brazilian giants Atletico Mineiro in a 2-2 home draw, scoring a total of 4 goals in 10 Copa Libertadores games played.
2013–14 season
For the 2013-14 Liga MX season Martínez was given the club's number 10 jersey. On August 4, Martínez scored his first goal of the season, in a 2-1 loss to Monarcas Morelia. A week later on August 10, he scored his second, in a 2-0 home win over Pumas UNAM. On August 23 Martínez scored his third, in a 1-1 home draw against Santos Laguna. On August 9 he scored his first goal ever in a Concacaf Champions League group match, defeating Firpo 1-0. On September 7, Martínez scored his first brace of the season in a 3-0 home win over Veracruz. On September 16 Martínez scored in a 2-2 away draw against Chivas. On October 4 he scored the winning goal in a 1-0 home win over Querétaro.
U. de G.
2014–15 Season
On June 4, 2014 Martínez joined U. De G. on loan from Tijuana. On August 20, 2014 Martínez scored and gave Leones Negros a victory in la Liga MX over 20 years against Club León. On August 29, 2014 Martínez scored against his former team Tijuana and eventually ended a 1–1 tie. Martinez holds Mexican citizenship. On January 12, Martínez scored the first goal in 2015 for Leones Negros, defeating Monterrey 1–0.
Pumas UNAM
On May 24, 2015 Martínez joined U.N.A.M. He enjoyed a good first tournament with Pumas, registering 4 goals and 6 assists in the regular season. As Pumas advanced to the Ligilla, Martinez scored in the quarter-finals to give Pumas a 1-0 win over Veracruz and advance to the semi-finals. Martinez started the Clausura 2016 tournament having lost his regular starting spot to new signing Luis Quinones, despite limited game time Martínez scored a last minute equaliser in a 1-1 draw away to Atlas.
