It had to happen. The sizzling rookie was not going to stay on this ride of being untouched forever. For the first time this season, Papelbon gave up a run. It just so happened that it came in at a crucial moment -- in the top of the ninth inning of Wednesday night's 7-6 loss to the Blue Jays.
The first blemish on his otherwise impeccable start didn't seem to deflate Papelbon. Instead, he was antsy to get the ball again and start a new streak.
"No doubt about it, I want the ball [on Thursday]," Papelbon said. "There ain't no doubt about it. Best-case scenario would be a one-run ballgame, we take the lead and they give me the ball again."
Papelbon, the American League's Rookie of the Month for April, entered Wednesday's action with a scoreless innings streak of 21 1/3 that dated back to Sept. 19, 2005, at Tampa Bay.
On this night, it was simply not to be. Entrusted with a tie game, Papelbon gave up singles to Lyle Overbay and Gregg Zaun, and then an RBI double to right field off the bat of Russ Adams.
"This is a bump in the road right now for me, but it's a long season. It's still basically the first month of the season, and I still have a long way to go and I still have a lot more innings to pitch," Papelbon said. "I'm just going to take this, learn from it and do my homework, study some film, see what happened and move on."
Catcher Jason Varitek already has a pretty good idea of what Papelbon will see when he looks at the tape.
"Pap threw the ball fine. A couple of balls found holes, we had two guys on and he got a split up and [Adams] put it down into the corner, and that was the difference," said Varitek.
In other words, there can be a fine line between being invincible and proving to be fallible. Papelbon is eager to jump back on the other side.
"I learned that you can't go out there and just throw the ball over the plate and expect to get outs," Papelbon said. "In the big leagues, that's just not going to happen. When I go out there, I have to be on my game each and every time. I didn't feel 100 percent, and I didn't feel the best I have in the past, but that's just part of the long season in the baseball game."
Making Papelbon's first loss of the season particularly painful was that the Sox had just come back to tie the game in the bottom of the eighth on a single to right by Mike Lowell. For the third baseman, it was hit No. 1,000 in his career.
"We kept clawing back," said Lowell, who went 3-for-4. "We came back about three times. To lose like that, that hurts. It's still early, we're still playing pretty good baseball."
Except against the Blue Jays. The Sox are 2-5 against Toronto and 13-7 against everyone else.
The anticipated duel between Roy Halladay and Josh Beckett fizzled early, with the teams trading three-run rallies in the second inning.
In a game that had its share of momentum swings, the Blue Jays regained the lead in the top of the fifth. With runners on first and second and two outs, Overbay came through with an RBI single to right field.
Beckett labored through five innings of work, allowing five hits and four runs over five innings while striking out two. He threw 101 pitches, which is why he didn't come back out for the sixth.
"I thought I executed some pitches, and they hit some good pitches," Beckett said. "It's a tough lineup and our guys did one [heck] of a job fighting back especially after giving up three runs that early. "
Similarly, Halladay never seemed to be in command. The Sox came back in the sixth, when Manny Ramirez ripped a ground-rule double down the left-field line and later scored on a single to right from Lowell. Wily Mo Pena then banged another clutch hit, this one an RBI double to right-center that scored Lowell all the way from first and put Boston back in front at 5-4.
Frustratingly for the Red Sox, the lead did not last long. Keith Foulke, after retiring the first two batters in the seventh, gave up a double to Overbay. That set up Shea Hillenbrand to haunt his former team with a rocket two-run homer over the Green Monster in left-center to put Toronto right back on top at 6-5.
"He has been doing such a great job," Francona said of Foulke. "We had [Mike] Timlin up and they had [Eric] Hinske over there, so you have to pitch to one of them. And Foulke had been throwing so well. We just obviously want to keep it in the ballpark at that point."
But Boston would come back one more time, only to see Toronto come back and take the lead for good.
"Tonight was a tough night for me," said Papelbon. "My pitches weren't very good and my pre-pitch routine wasn't very good, and neither was my post-pitch routine. I'll work on it and learn from it and that's all I can do."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.