BOSTON -- How could anyone know what to expect when James Paxton stepped on a Major League mound for the first time in more than two years and faced the Cardinals on Friday night?

Certainly it wouldn’t have been fair to expect nine strikeouts over five quality innings. Or a crisp fastball that topped out at 97.8 mph.

But as the lefty made his long-awaited debut for the Red Sox 17 months after he signed with them, he did both of those things, serving as the standout performer in Boston’s 8-6 loss at Fenway Park.

“It was a long time [coming],” said Paxton. “I was focused on finding my rhythm out there and letting it rip.”

Let it rip is exactly what Paxton did. Paxton allowed four hits, two runs and one walk while striking out nine and throwing 87 pitches (58 for strikes).

“He looked like the guy that was pitching in Seattle a while ago,” said Red Sox manager Alex Cora. “The fastball was playing, the breaking ball got better through the outing, the cutter, he dotted a few of those. He was in control.”

Paxton was in line for the win when Enmanuel Valdez and Connor Wong roped back-to-back homers in the bottom of the fifth, but the bullpen couldn’t hold it.

That took nothing away from what a big night this was for the man known as the Big Maple.

“That was awesome, watching him pitch today,” said Red Sox closer Kenley Jansen, who was charged with his second blown save of the season. “It gave me goosebumps. Talk about a guy who hasn’t competed in a couple of years to get nine strikeouts, he was sharp. The first thing I did [when he came out] was give him a hug and tell him, ‘Welcome back.’ He’s going to be a huge part for us. Just feel good about this and continue to build on this and be ready for the next one.”

Impressively, Paxton was able to channel his emotions and brush off the rust on a night his only blemish was a two-out, two-run homer off the bat of Nolan Arenado in the top of the first.

“Honestly, it kind of felt like my debut all over again after being out for so long,” said Paxton. “All those emotions -- you’re nervous, you’re excited, all that. I just focused on getting ready for the game with everything I had.”

Results aside, the win for Paxton on Friday was just the fact that he made it back after such a long road of rehab from Tommy John surgery and other assorted injuries. The fact he almost looked like his vintage self made it more special.

“I felt like myself out there,” said Paxton. “It was really nice to be pitching in a big league stadium again with all the adrenaline. The fans were fantastic out there. Just had a lot of fun.”

Next up for Paxton will be a start at San Diego on May 19. There is certainly plenty to build on.

Of the 39 swings the Cardinals took, Paxton generated 12 whiffs. In the fourth, he achieved a career first, striking out three batters looking in the same inning.

As he walked back to the dugout following his final frame, his coaching staff and teammates swarmed him with congratulations.

At last, Paxton felt like a full-fledged member of the Red Sox.

“When I was all done, getting congratulations from all those guys was really nice. They know what I've been through and how long it’s been,” said Paxton. “It’s really nice to be out there pitching, being part of these guys. I'm excited to keep going with this group.”