The 41-year-old righthander has won each of his four starts this season -- his first in the NL after 20 in the American League. The six-time Cy Young Award winner capped a five-run third inning with a two-run single.
Clemens' hit staked Houston to a 7-1 lead. With the big lead, Clemens was not nearly as sharp as he has been this season as he allowed five runs and nine hits in 5 2/3 innings.
Clemens walked three, struck out seven and picked up career victory No. 314, tying him with Hall of Famer Gaylord Perry for 15th place all-time. Phil Niekro is 14th with 318 wins. The seven strikeouts gave him 4,125 -- 11 shy of Steve Carlton for second in history.