Left fielder Jason Lane hit .299 with 23 home runs and his 104 runs batted in tied for the league lead.
Johnson walked two in a row to load the bases in the third, but he retired Jason Lane on a fly out to escape.
Jason Lane, who batted .272 in 136 at-bats in 2004, is the leading candidate to play center.
Jason Lane led off the Astros' fourth with a home run to left-center field.
The Astros had the best chance of scoring in the sixth, but Jason Lane struck out with the bases loaded to end that rally.
Jason Lane, who wore Wynn's 24 before the ceremony, changed his number to 16 as a result.
In his first move, he traded Jason Lane to the Padres on September 24.
Mike Lamb was walked intentionally, loading the bases, but Jason Lane struck out.
The head coach is Jason Lane and they are planning to announce their home venue in the following weeks.
The Astros took a 4-0 lead in the fourth inning on a bases-empty homer by Jason Lane.