On April 28, 2007, the Astros purchased the contract of top minor league prospect Hunter Pence. He debuted that night, getting a hit and scoring a run. By May 2007, the Astros had suffered one of their worst recent losing streaks (10 games). On June 28, second baseman Craig Biggio became the 27th MLB player to accrue 3,000 career hits. Biggio needed three hits to reach 3,000 and on that night he had five hits. That night, Carlos Lee hit a towering walk-off grand slam in the 11th inning. Lee later quipped to the newsmedia that "he had hit a walk-off grand slam and he got second billing", considering Biggio's achievement. On July 24, Biggio announced that he would retire at the end of the season. He hit a grand slam in that night's game which broke a 3–3 tie and led to an Astros win. In Biggio's last at bat, he grounded out to Chipper Jones of the Atlanta Braves.