Dennis Martinez (12-3) of Montreal lost his second successive start after winning 11 consecutive decisions.
It was his second successive start after beginning the season with 14 relief appearances.
Abbott (2-4) struck out four and walked three as he won his second successive start after opening the season with four losses.
August (6-6) won his third successive start, striking out two and walking four.
He has won three successive starts and five of his last six decisions.
Clemens (20-5) won his eighth successive start and kept his earned run average at 1.95, best in the major leagues.
The veteran pitchers have five victories between them, with four coming in two of the three times they have made successive starts.
McDowell and Hibbard had not lost successive starts entering last night's game.
Wells (5-3) won his fourth successive start, allowing two hits in seven innings, striking out six and walking four.
Tibbs (2-4) won his second successive start, allowing one run on five hits in six and a third innings.