Pitching for the first time in five years, Clemens tossed 3 1-3 scoreless innings Saturday night for the Sugar Land Skeeters of the independent Atlantic League.
Clemens faced the Bridgeport Bluefish and struck out two, including former major leaguer Joey Gathright to start the game. He allowed one hit without a walk and threw 37 pitches.
Scouts from the Houston Astros and Kansas City Royals were on hand to watch Clemens' comeback -- for however long it lasts and wherever it leads.
He certainly was happy to be back on a diamond instead of in a courtroom. In June, the seven-time Cy Young winner was acquitted of charges he lied to Congress when he denied using performance-enhancing drugs.
Clemens, who last pitched for the New York Yankees in 2007, worked a 1-2-3 first inning and fanned two. His fastball was clocked at 88 mph, and he mixed in curves and splitters.
Wearing the No. 21 that he sported during his rise to fame with Boston nearly three decades ago, Clemens got a big cheer when he took the mound.
After whiffing Gathright, Clemens retired Luis Figueroa on a grounder and struck out Prentice Redman to end the inning. The sellout crowd, with many fans wearing Skeeters T-shirts with Clemens' name on them, gave him another loud ovation.
Clemens didn't allow a hit until a single by James Simmons with two outs in the second inning. He retired the next batter to end the eight-pitch inning.
Clemens has a bit of a belly that scores of 50-year-olds have, but he was effective enough against many hitters who were almost half his age.
The Rocket hasn't committed to pitching more than one game for the Skeeters, but some believe this is the first step in an attempted return to the majors.
Clemens is set to appear on the Hall of Fame ballot going to voters late this year. If he plays in a major league game this year, his Hall consideration would be pushed back five years.
Clemens, who wore gray cleats with bright yellow accents, needed 13 pitches to get through a perfect third inning. He threw one more pitch after that and Figueroa lined out to end Clemens' night with the Skeeters on top 1-0.
He received a standing ovation as he left. He stopped to tip his cap to the appreciative crowd before heading to the dugout to begin recuperating and see how his body responds to his big night.
Clemens earned about $160 million and won 354 games in a 24-year career with the Red Sox, Blue Jays, Yankees and Astros. His 4,672 strikeouts are third-most and he was picked for 11 All-Star games.
Clemens bounded into the home clubhouse a little more than an hour and a half before the game wearing a gray Longhorn shirt, jeans and cowboy boots and bellowed, "how we doing, how we doing?" as he walked through shaking hands with his teammates.
His highlighted blond hair was a bit spiky on top, causing a couple of his teammates to ask each other if he'd gotten a new haircut.
Clemens has spent much of his time out of baseball defending his reputation.
He was accused by former personal trainer Brian McNamee in the Mitchell Report on drugs in baseball of using steroids and HGH, allegations Clemens denied before Congress. The Justice Department began an investigation into whether he had lied under oath, and in 2010 a grand jury indicted him on two counts of perjury, three counts of making false statements and one count of obstructing Congress.
He was acquitted of all the charges on June 19 after a 10-week trial and had largely stayed out of the public spotlight until now.
Many of his former teammates have said they believe that he could pitch again in the majors.
Clemens had two great seasons with the Astros after he turned 40, going 18-4 with a 2.98 ERA in 2004 to win his record seventh Cy Young Award. He was 13-8 with a career-low 1.87 ERA in 2005 while helping his hometown Astros reach their only World Series, and the team has already said it wouldn't rule out bringing him back this year.