Red Sox starting pitcher Justin Masterson was on target during his major-league debut yesterday at Fenway Park. Masterson allowed two hits and one run in six innings against the Angels.

The Providence Journal / Mary Murphy

BOSTON — A few years from now, or maybe even in only a few months, not many people are likely to remember that the Red Sox bullpen blew a lead yesterday and the Sox lost to the Angels, 7-5.

It is very likely, though, that many will remember they were there the day Justin Masterson made his major-league debut.

In the long run, the defeat the Sox suffered is not likely to mean much. Yes, the bullpen struggled again and the Angels rallied to win. But so what?

That pales in comparison with the work turned in by the latest phenom in the Boston organization. Whether it is later this season (which is likely), or farther down the road, Sox fans found out the organization has another outstanding prospect.

Masterson, a 6-foot-6, 250-pound right-hander, pitched six strong innings. He allowed only two hits and one run (a homer by Mike Napoli) with four walks and four strikeouts. The 23-year-old from Beaver Creek, Ohio, has been compared favorably to Clay Buchholz as being the best of the host of young pitchers in the Boston organization. He showed why.

Called up from Portland to make an emergency start, he was impressive.

“He handled himself just like you would hope,” said Sox manager Terry Francona. “That’s a lot to ask a kid coming out of Double-A. He competed, he had composure, he knew what he wanted to do and he did it. He did a great job. As an organization, I don’t think we could be prouder.”

“It was just fun,” Masterson said. “I was happy to have the opportunity.”

It will be his only appearance for the time being. He is being sent back to Portland to continue to pitch every five days. In his first four starts with the Sea Dogs, he compiled an earned run average of 0.95 with 23 strikeouts and five walks in 19 innings. Kevin Cash, his catcher yesterday, had worked with him several times in spring training.

“He was so composed,” Cash commented. “He was drastically improved, even from spring training.”

Masterson does not throw overly hard, his best being in the low 90s. But he has a great sinker. He allowed only three fly ball outs.

“On fastballs, he threw predominantly sinkers unless we were trying to go way off the plate,” Cash said. “He mixed a lot of pitches in, threw everything for strikes. That was key early. He threw it for strikes.”

In addition to having big-time ability, Masterson also has been praised for being mature beyond his years off the field. The son of a pastor, he is articulate and personable.

“I might have been more nervous for him,” Cash said. “He wasn’t showing anything, especially that first inning. He kind of coasted right through it. Then he kept it up the rest of the game. When he came out to warm up in the pen, it was like he’s been doing this for 10 years. . . I’m looking forward to the next time I get to catch him. He’s going to have a bright future, I would imagine.”

Masterson pointed out that he had pitched once before at Fenway, in the Futures at Fenway game.

“Surprisingly, that helped me calm the nerves,” he related. “With the fans cheering and the park. This is how it was supposed to be. It was pretty nice.” Because he had been notified Wednesday night, his parents, his wife and several friends all had time to get to Fenway to watch him in person.

He was not at all surprised when the Sox informed him he was heading back to Portland.

“I’m going to go back and continue to show them I’m ready to go,” Masterson said. “When the time comes that I’m needed, that’s when I’ll be up here.”

Masterson threw 95 pitches (58 strikes) and left with his team ahead, 3-1. Coco Crisp, playing for the first time in nine days, had helped give him a lead. Crisp drove in Manny Ramirez with a fielder’s choice grounder in the second and then doubled to drive in a run and scored on a double by Cash in the fourth.

The relievers lost it. Sox pitchers needed 52 pitches to retire the Angels in the seventh. Los Angeles scored four times in the inning off Javy Lopez, Manny Delcarmen and Hideki Okajima. The Angels added single runs in the eighth and ninth innings so that a two-run homer by David Ortiz in the ninth turned out to be meaningless.

pkenyon@projo.com