ROGER CLEMENS never is really alone on the mound. Some of the great pitchers of the past are there with him in his fiery attitude and approach, and, as always, his family is there in spirit to support him.

The Rocket last night had 55,214 Yankee Stadium fans pushing, willing him forward, too. “I felt them in my chest,” he said.

This was the time for teammates, family, friends and fans to help Clemens succeed in his quest for 300 wins with a magnificent 5-2 win over the Cardinals.

“We wanted to do it for Roger,” said Mariano Rivera, who picked up his eighth save with a perfect ninth. “He’s always been there for us.”

The traveling show had dwindled a bit. Clemens’ wife, Debbie, and their four “K” kids were there to fill historical baggies of Stadium mound dirt, even though the youngest, Kody, managed to put a hole in his bag. That’s what 7-year-olds do. Clemens’ older sister Janet represented Roger’s four other brothers and sisters.

“It was worth the wait, and to do it here in New York is so special,” said Janet, who has been at the last four stops along the 300 Quest Tour.

Janet also displayed typical Clemens’ humor, a trademark of the family that had to survive difficult times growing up, but survived by sticking together.

“I told Roger in spring training that there were some ballparks I had not seen yet, that I wanted to visit this year,” Janet said with a laugh, “but I didn’t expect to see them all in the same month.”

The Yankees’ bats came alive last night, bashing three home runs. The Rocket was masterful, striking out 10. Along the way he picked up strikeout No. 4,000, not a bad night’s work.

“Thank goodness the Griswold Tour is over,” Clemens joked.

How about official scorer Howie Karpin, who filled in Clemens’ line of 62/3 innings: six hits, two runs, two walks and 10 strikeouts? Karpin last worked Wednesday night, the Astros’ six-pitcher, no-hitter against the Yankees.

“This was the Magical History Tour,” he said.

In more ways than one.

Clemens tour started here on May 26, an 8-4 loss to the Red Sox, then moved onto Detroit and Chicago before a lucky return to the stadium on Friday the 13th.

His major league quest began in 1984, when the non-roster right-hander made the Red Sox and posted a 9-4 record.

“I remember that first win and the first 20-strikeout game [two years later],” Debbie said outside the clubhouse after the victory. “And then our life changed.”

Back then, 300 victories was only a dream. Clemens would spend 13 years in Boston and touched many lives in many ways.

Boston Globe columnist Dan Shaughnessy was at the Stadium last night reporting for his newspaper. He was there for the entire Boston ride and has some incredible memories of Clemens. Not all of them occurred on the field.

Shaughnessy is the first to admit his relationship with Clemens had its ups and downs.

“Mostly downs at that point,” Shaughnessy said of the 1993 season. That year Clemens went 11-14. That November Shaughnessy’s 8-year-old daughter Kate was diagnosed with leukemia.

“One of the few days she was home this giant box arrived from UPS,” Shaughnessy said. “The driver saw the name Shaughnessy and the return address: R. Clemens, Katy, Texas, and thought the thing was ticking.

“We could barely get it through the door. We opened it up and it was a giant white teddy bear with an autographed ball wrapped around inside it and it said, ‘Get well soon.’ “

Young Kate lovingly called the big white bear Clementine.

Kate graduated high school last week. She still has that darling Clementine of a bear.

Last night was Clemens’ time, and the big white bear became that much more special.