Richard had a pretty extraordinary game, allowing 11 hits, six walks and five runs in eight innings of work, but he struck out 12. Seaver, on the other hand, only struck out two, but allowed seven hits, two walks and three runs in six innings to get his seventh win of the season.
The big problem for Richard came in the bottom of the sixth. He gave up a single to future Astros hitting coach Harry Spilman, who was pinch-hitting for Seaver. Then, Ken Griffey, Sr. bunted for a single, which moved Spilman to third. Cesar Geronimo added a second consecutive bunt single to third baseman Enos Cabell, who threw the ball away, allowing Spilman to score and Griffey and Geronimo to move up a base. That tied the score at 3-3.
That's when Joe Morgan was intentionally walked to load the bases. Richard struck out Johnny Bench for the first out of the inning, but his control left him on the next batter and Richard walked Dan Driessen to give the Reds a 4-3 lead. Ray Knight padded the lead in the next at-bat with a sacrifice fly to center field, scoring Geronimo from third.
Doubles by Craig Reynolds, Cesar Cedeno and Art Howe in the top of the sixth gave Houston a 3-2 lead and scored another run in the top of the eighth. Denny Walling and Cabell had back-to-back singles before Howe drove in another run with a sac fly.
This was also the year before Joe Morgan was traded back to Houston, but the Astros were still comfortably in first place at this point in the '79 season. In fact, this game moved the second-place Reds up to nine and a half games behind Houston. The Astros did not win their first pennant this season, which may have been one of the reasons why they made the Morgan trade in the offseason.
Here's a graphic replay of the game, thanks to Back to Baseball.