He allowed one run on three hits, including a home run, did not walk a batter and had six strikeouts.
"I felt great," Clemens said. "It was a circus atmosphere here. It took some time for me to get locked in. I thank the Lexington fans for coming out. It was a beautiful night. We had a good time with it."
Clemens retired the first two batters he faced before Lake County center fielder Johnny Drennen connected on a 2-2 pitch and sent it sailing over the Party Deck in right field to give the Captains a 1-0 lead.
In addition to Drennen's home run, Clemens also allowed a single, double and hit a batter.
Clemens will workout with the Astros before moving on the Double-A Corpus Christi, where he is scheduled to start on Sunday.
If all goes as planned, Clemens will start June 16 for Triple-A Round Rock, then make his debut with the Astros on June 22 at Minute Maid Park in an Interleague Play matchup with the Minnesota Twins.
"[Tonight] was one step down and two to go," Clemens said.
He tossed a perfect second inning with two strikeouts.
Clemens finished by striking out the last two batters he faced in the third.
He acknowledged the Lake County players before exiting the mound and emerged from the Legends' dugout moments later for a curtain call at the bequest of the capacity crowd.
More than 130 media credentials were issued for Tuesday's game. ESPN carried portions of Clemens' outing live via MiLB.TV.
The folks in Lexington took full advantage of Clemens' appearance. T-shirts emblazoned with "Rocket Launch 06 June 2006" were sold in the team shop and Clemens' No. 22 was stenciled on the infield dirt behind second base.
Clemens' son, Koby, started for the Legends at third base.
"It ranks right up there," said Clemens of playing alongside his son. "There's nothing like it. I'm happy a lot of our family was here to see it."
The Astros declined Clemens salary arbitration making him ineligible to sign with the club until May 1. After being courted heavily by the Yankees, Red Sox and Rangers, Clemens decided to return to Houston where he's gone 31-12 with a 2.43 ERA in 65 starts the past two seasons.
The Astros signed Clemens last week to a one-year minor-league contract worth $322,000. Once he joins the Astros, Clemens' Major League deal will be valued at $22,000,022.
Clemens went 13-8 last season with a Major League-leading 1.87 ERA, helping Houston reach its first World Series in franchise history.
Clemens earned his seventh Cy Young Award in 2004 when he went 18-4 with a 2.98 ERA in 33 starts for the Astros. He has 4,502 career strikeouts which trails only Nolan Ryan on the all-time list.
"I took it all in," said Koby Clemens. "It was great. I think he raised everybody's game. The atmosphere was very different with him on the mound."