FORT MYERS, Fla. (AP) – Jonathan Papelbon took the next step in his transition from closer to starter for the Boston Red Sox.

He started.

Papelbon pitched his first first inning in a major-league exhibition game this year and struggled with the leadoff hitter but was happy with his performance. Chris Denorfia homered on a 3-2 pitch in Cincinnati’s 2-1 win Saturday.

In 3 2-3 innings, Papelbon allowed five hits and one walk, hit one batter and struck out five. In his other two outings against major-league teams this spring, he relieved Tim Wakefield and was outstanding – five scoreless innings and eight strikeouts with only one hit and one walk.

“I think I fell behind way too many hitters” Saturday, Papelbon said. “and for me it’s going to be important to get that game started out on a good foot those first couple innings. But that’s a learning experience.”

Papelbon, who relied on a fastball and splitter last season, must expand his assortment of pitches as a starter. On Saturday in his first appearance since starting a minor-league game last Monday, he effectively mixed all five of his pitches into the 72 (42 strikes) he threw and was pleased with his workload.

“That’s a big, big plus for me, getting my body to that stamina that I need to get, everything building up to a guy that can go seven or eight innings,” he said. “I’m feeling really good about my routine, my repertoire, how my pitches are coming along, everything.”

Papelbon is coming off an epic rookie season as a closer.

Among pitchers who threw more than 50 innings, his 0.92 ERA was the eighth lowest in major-league history and his .167 opponents batting average ties him with Pedro Martinez’s 2000 season, when the former Boston ace won the Cy Young award, for the major-league record.

“For me, being a starter is a whole different animal,” Papelbon said. “As a starter, you’re trying to get deep into ballgames and get ground balls.”

Even though the main area of uncertainty on this year’s club is finding a reliable closer, the decision to change Papelbon’s role seems sound for several reasons and the Red Sox are committed to it.

He missed the last 30 games last season with a shoulder injury, and the club believes the routine of having to be prepared to pitch every day – and being in games two or three consecutive nights – might have supplied some stress.

If he stays healthy, Papelbon could triple the 68 1-3 innings he threw last year. Because he came to the majors as a starter, he’s returning to the role he had been groomed for before taking over for injured closer Keith Foulke early last season.

“I’ve been trying to develop my pitches back that I had two years ago when I was starting,” Papelbon said, “So, it’s kind of like riding a bike. You go back to your old things that you did, or I did back in ’05.”

To make a smooth conversion to starting, Papelbon needs the same confidence he showed as a closer and a wider variety of pitches. He had success last year with the accelerating four-seamer and diving splitter. He’s been working on his slider, curveball, and two-seam fastball and he got plenty of practice with all three against the Reds.

“That was another big positive out of my outing,” he said. “The fact that I threw my curveball for strikes, I threw my slider for strikes and I threw my slider for out pitches.

“I was definitely working on my two-seam a lot today.”

Manager Terry Francona thought Papelbon’s breaking balls were among the best he’s thrown this spring, but also noticed similarities to how he threw last year – particularly the pitch he closed out so many games with.

“I actually thought today at the end of the game (was) one of the best fastballs he threw. I think he agrees. The umpire actually stopped me and said the same thing,” Francona said. “He seemed like he got into a little bit of a groove.”

The thought of Papelbon getting stronger as the game goes on is a scary proposition for opponents, considering his success last year as he got closer to the end of games.

“I’m going to use a little bit of that closer mentality when I need to,” he said, “but, at the same time, go about my business as a starter and get the ball game under way and get my team back in the dugout.”

AP-ES-03-17-07 1918EDT