Wood made his first appearance in the Major Leagues on April 12, 1998. In his fifth career start, on May 6, he threw a one-hit, no walk, 20-strikeout shutout against the Houston Astros in Wrigley Field, tying Roger Clemens' record for strikeouts in a nine-inning game and breaking Bill Gullickson's single-game rookie record of 18 strikeouts in 1980.
Wood allowed only two baserunners: Ricky Gutiérrez on an infield single and Craig Biggio who was hit by a pitch with a count of two strikes and one ball. (Biggio had led the league in that category each of the previous three years.) Only seven balls reached fair territory. Five were grounders that never left the infield (including Gutierrez's hit), one was a short fly along the right field line, and another was a fly to center. A foul pop was caught by first baseman Mark Grace and the remaining twenty putouts were credited to catcher Sandy Martínez, who caught the entire game. Wood had no special advantages – the Astros went on to lead the league in on-base-percentage, and all of the regulars were in the lineup, including the four who finished the season batting over 300. Not surprisingly, the performance garnered a game score of 105 – the highest number ever calculated for a pitcher in a nine-inning game.
