José Ynocencio Sosa (December 28, 1952 – June 8, 2013)[1][2] was a Dominican Republic relief pitcher in Major League Baseball who played from 1975 through 1976 for the Houston Astros.

[4] Sosa was signed by the Astros as an amateur free agent in 1970 and started his career in their minor league system, playing for them at three different levels before joining the big club late in the 1975 midseason.

[3] During a game against the San Diego Padres on July 30, 1975, Sosa secured his place in the record books when he belted a three-run home run off Danny Frisella at the Astrodome, to become both the first Dominican pitcher and the first Astros player ever to hit a home run in his first major league plate appearance.

[3] In a two-season career, Sosa posted a 1–3 record with one save and a 4.60 earned run average in 34 games (two starts), allowing nine runs on 67 hits and six walks, while striking out 36 over 58+2⁄3 innings of work.

[6] Sosa also pitched for the Leones del Escogido of the Dominican Winter League from 1977 to 1978.