The Houston Astros purchased Niekro's contract from the Braves for $35,000 in 1975. He blossomed into a dominant pitcher as he perfected his knuckleball in Houston, going 21–11 in 1979 and 20–12 in 1980, to become the first Astros pitcher to win 20 games in consecutive seasons. He also made the National League All-Star team in 1979, a season in which he led the league with his 21 wins and five shutouts, won the "TSN" Pitcher of the Year Award, and ended second in voting for the Cy Young Award behind Bruce Sutter. 1979 also saw the Niekro brothers tie for the wins leader in Major League Baseball, marking this the only year that two brothers shared this honor.