Don Cardwell, who threw a no-hitter with the Cubs and one of the key figures of the Miracle Mets' 1969 World Series run, died on Monday at the age of 72. The cause of death was not immediately known.

"He was a tremendous mentor to the young guys on our staff," Mets Hall of Famer Tom Seaver said in a statement through team spokesman Jay Horwitz. "When he said something, you listened. He was the ultimate professional on and off the field. Just a tremendous, tremendous guy -- and a big part of everything we accomplished that year."

Cardwell split his career among five teams, but was perhaps best known for the role he played leading up to the 1969 World Series. After posting a 3-9 record over the season's first four months, Cardwell strung together five straight wins down the stretch to help the Mets overtake the Cubs in the National League East.

He won just 20 total games in four seasons with the Mets, but the quality of those final five certainly trumped all else. Beginning the streak with a stretch of 28 scoreless innings, Cardwell went on to allow just one run over the five victories, good for a 0.26 ERA. By the time he finally lost a game on the season's final day, Cardwell's Mets -- thanks also to a rotation that included Seaver, Jerry Koosman and Gary Gentry -- had clinched the division title.

He pitched one perfect relief inning in Game 1 of the World Series, marking the only postseason appearance of his career.

"He was a three-quarter-arm guy with a real good sinker, slider. Hard stuff," former Mets teammate Ron Swoboda said. "I remember hitting off him before we got him from Pittsburgh and you really had to convince yourself from the right-hand side to stay in there against him."

Part of his success came from his demeanor. Swoboda recalls Cardwell sticking up for his teammates during a fight with the Astros in 1969, and sending Houston third baseman Doug Rader flying to the ground.

"I think it helps calm you down when you've got a guy like that who's ready to do what it takes," Swoboda said. "When it got to fist city you needed some guys that were ready to go."

Cardwell also played for the Phillies, Cubs, Pirates and Braves, and finished his career with a 102-138 record and a 3.92 ERA.

It was with the Cubs that Cardwell placed his first claim to fame, firing a no-hitter against the Cardinals on May 15,1960 -- in his first start with the team.

"All you-know-what broke loose with people coming on the field," Cardwell told WGN Sports back in 2005. "The ushers tried to hold people back, but there was just no way. I was trying to get off the field, because there was just so many people right on top of you. For years, I've told people I just didn't want to spike anybody."

After retirement, Cardwell began working in automobile sales, where he was at the time of his death. Cardwell is survived by his wife, Sylvia, three children, five grandchildren and three sisters.

"We need more Don Cardwells in the world," Junie Michael, who worked with Cardwell selling cars for more than 35 years, told the Associated Press on Monday. "I just can't say enough about what a positive influence he was on our community.

"I've never met a better guy in my whole life."

A public memorial service will be held at 11 a.m. on Thursday.