Nathan had not given up a run or even a hit in four previous one-inning spring training outings.
He said his surgically-repaired right elbow still felt fine. And the outing happened during spring training.
Twins starter Francisco Liriano, in line to start the second game of the regular season, struck out two, walked two and gave up four hits and no runs in three innings.
Phillies starter Michael Stutes, expected to begin the season in Triple-A, struck out one, walked one and did not give up a run or a hit, lowering his spring ERA to 1.00.