Mariano Rivera posts his 300th career save in a Yankees’ 7 – 5 victory over Tampa Bay. He also becomes the first Yankee and 17th reliever in major league history to reach the milestone.
On May 28, 2004 — Mariano Rivera posts his 300th career save in a Yankees’ 7 – 5 victory over Tampa Bay. He also becomes the first Yankee and 17th reliever in major league history to reach the milestone.
Source:
Baseball Reference May 28