Antal Barát-Lemberkovits, as a military officer started his sports career in rowing, skiing and skating in the colors of the Buda Honvédtiszti (Military Officer) SE. However, he achieved his most significant results in shooting as a member of the Honvéd Tiszti Sportegyesület. He participated in shooting at the 1932 Olympics. In the small bore-rifle, prone, 50 meters, discipline he finished in 18th place with 285/300 points despite one of his shots being aimed at the wrong target. The error eventually cost Barát-Lemberkovits a chance of the gold medal, as he finished 9 points out of the gold medal.
In 1935 he was a member of the Hungarian team that won the World Championship title in the team rifle event. He was a 15-time individual and a 20-time Hungarian team champion.
In 1934, he changed his surname to Simonfay, and then he also competed as Antal Simonfay and Antal Simonfay (Lemberkovits).
In 1934, he wrote a study in the Hungarian Military Review entitled „The Training of the Target Shooter”, then in 1938 on „The Cooling of the Machine Gun Barrel” and „Shooting in Modern Pentathlon”.
In 1948, he and his family emigrated to Argentina, where he continued to compete in sport shooting.