Darwin, or Dr. Death as I remember him, threw 7 2/3 innings, giving up four hits, five walks and five strikeouts. Dave Smith pitched the final 1 1/3 innings to pick up his 11th save of the season. Dravecky only gave up two hits and one run in six innings, but fell to 1-6 with the loss.
The Astros staked Darwin to his big lead in the third inning when Alan Ashby led off with a single. Dickie Thon followed with a single, pushing Ashby to second. After a Danny Darwin fly out, Billy Hatcher walked to load the bases with one out. That's when Billy Doran hit into a fielder's choice to the second baseman, who flipped to short for the second out of the inning, which allowed Ashby to score from third.
This was not a good San Diego team, as they were 15-44 at this point. However, they had two guys in the middle of the lineup hitting .367 with OPS' over .950 in Tony Gwynn and John Kruk. The problem, like many bad teams, is that no one else in the starting lineup had an OPS over .720.
Darwin was acquired from the Brewers down the stretch in 1986 for Don August and Mark Knudson and was great. He had two somewhat lackluster seasons (in light of pitching in the Astrodome), before really turning it on in '89 and '90, going 22-8 with an ERA+ of 158 over that stretch. He left after the '90 season as a free agent, signing with Boston and pitching for eight more seasons, bringing his career total to 21 seasons in the big leagues.
Here's a graphic replay of the game, thanks to Back to Baseball.