Labruna's debut in the Primera División was in replacement of José Manuel Moreno who had been suspended by the club, wearing the number 10 shirt. The match disputed on 18 June 1939 in La Plata against Estudiantes, which defeated River by 1–0. His goals scored and outstanding performances caused that Moreno had to play on the right side of the field when he was allowed to play again. Labruna played in River for 20 years, winning 9 domestic championships with the team and being the top scorer twice. He was part of his club's legendary team along with Juan Carlos Muñoz, José Manuel Moreno, Adolfo Pedernera, and Félix Loustau, where he played as an inside-left forward. Although this attacking line only disputed 18 games with those players, they were regarded as one of the best forward line in the history of Argentinefootball. They were nicknamed La Máquina due to their skills with the ball and synchronized play. Coach and former player Carlos Peucelle said that his team was formed by "A goalkeeper and 10 forwards", using an imaginary "1–10". Labruna holds a number of records for River Plate, including his record of 16 goals in the superclásico derby with fierce rival Boca Juniors. In 1959, Labruna left River Plate having defended club's colors in 515 matches and scoring 317 goals, 293 in goals what made him the all-time highest goalscorer in the Argentine first division along with Arsenio Erico, a record that remains nowadays. He later played two seasons in the Chilean C.S.D. Rangers, and Uruguayan team Rampla Juniors of Montevideo, before returning to Argentina to finish his career at Platense, when he was 43 years old. Labruna played 37 matches for the Argentina national team, scoring 17 goals. He also won two South American Championships and as a nearly 40-year-old he played in the final phase of 1958 FIFA World Cup held in Sweden. As other great players of his generation, Labruna could not participate in other World Cups due to the event's suspension during World War II and later for the decision taken by the Argentine Football Association, which did not compete in the World Cups of Brazil and Switzerland.
Labruna had two sons, Daniel and Omar, who worked with Ramón Díaz in River Plate and then coached Olimpo de Bahía Blanca and other teams. Labruna died on September 19, 1983 from a heart attack, at 64 years old. He is buried at La Chacarita Cemetery in Buenos Aires. Every September 28, River Plate's fans celebrate the "International River Plate Fan's Day" as a tribute to one of the club's greatest idols.
