Here was Kelly, possessor of an upper-90s fastball he threw 65.5 percent of the time last season, third most among American League pitchers who made at least 25 starts, according to ESPN Stats & Information research. And there were the previously undefeated Baltimore Orioles, mashers of fastballs to the tune of a .357 average, 1.117 OPS and nine home runs this season.
On paper, it was a bad matchup for the Red Sox.
But Kelly's evolution from thrower to pitcher began to take root during the final two months of last season, when he started relying more on his offspeed pitches. And in holding the Orioles to two runs in five bend-but-don't-break innings of a 4-2 victory, Kelly demonstrated that he can have success with his changeup and curveball.
In the first inning, for instance, Kelly struck out slugger Chris Davis, finishing him off with three consecutive changeups. Last year, in a similar situation, he probably would have tried to overpower Davis -- and in all likelihood, he would have lost.
"It was good," Kelly said. "I think the only bad changeup I threw was the double (Manny) Machado hit off the wall. If that’s down and away, where I tried to place it, maybe it’s a ground-ball rollover, weak contact. But the start before I don’t even know if I threw one changeup. It was a point of emphasis going into the game today."
Kelly continued the starting rotation's alarming streak of not pitching deep into games, leaving a rapidly overworked bullpen to record the final 12 outs. Between them, Matt Barnes, Tommy Layne, Junichi Tazawa, Koji Uehara and closer Craig Kimbrel did the job. Kimbrel gained redemption for his blown save in Monday's Fenway opener by striking out the side, including Davis, who had homered against him two days earlier.
And because of the work of the bullpen, Jackie Bradley Jr.'s tiebreaking RBI triple in the fourth inning held up as the decisive blow that handed the Orioles their first defeat.
Although Kelly labored at times, allowing seven hits and walking five batters, putting far too many men on base to remain successful, he was often bailed out by his defense. Second baseman Dustin Pedroia ranged into shallow left field to snare a relay throw and cut down J.J. Hardy at third base on what would've been a leadoff triple in the second inning.
It took 116 pitches for Kelly to get through the fifth inning, and if he hadn't struck out Caleb Joseph with the tying runs on base, it's doubtful the Red Sox would've left him in the game to face another batter.
But for a pitcher who is still learning to harness his arsenal of pitches, it represented a step forward.