MINNEAPOLIS -- Randy Johnson has seen a lot in his 21-year Major League career.

The D-backs left-hander never stops discovering new things about the game, some less pleasant than others.

Take, for instance, Friday night's game, in which the Twins beat the D-backs and Johnson, 7-2, in front of 29,069 at the Metrodome.

"Just when you think you've seen everything in this game," Johnson said, shaking his head. "Obviously, it was just the one inning."

The inning Johnson referred to was the third, when the Twins managed to score six runs. Aside from a single tally in the fourth, that was all they could muster off Johnson, who went the distance. It was the lanky left-hander's first complete game since Aug. 24, 2006.

"Pretty impressive to keep the resolve and focus and not have us go to the bullpen really early in the game," manager Bob Melvin said.

But at 44 years of age, Johnson can hear the clock ticking, and it is harder and harder for him to swallow moral victories. Johnson (4-5) has lost his last four starts and has allowed 21 earned runs in those games.

"The last four games that I've pitched have been extremely frustrating," said Johnson, who remained stuck on 288 wins. "I feel good, it's just frustrating, because in all those games, it's essentially been one inning, and today it was a big one inning."

The Twins didn't exactly tear the cover off the ball in the decisive third inning. It started when Delmon Young hit a grounder to third that took a funny hop on Mark Reynolds, whose throw across the diamond hit Young.

"I was set up for a backhand chopper, and it just hopped away from me, and I had to make an off-balance throw and it was a tough throw," Reynolds said. "It was a weird play."

The inning also included a bunt single and a pair of ground-ball singles. The ball that was unquestionably hit hard was Craig Monroe's two-run homer that capped the scoring.

"They got some seeing-eye singles up the middle and Monroe hit the home run," Reynolds said. "Just a tough day for Randy. He pitched well, just left that one ball up, and other than that, he pitched great."

Again, that was of little consolation to Johnson.

"Didn't make some pitches, and they got some hits, and it just kind of snowballed before I could put the fire out," Johnson said. "I thought a couple of balls were hit hard. After that, I seemed to pitch much better."

By then, however, it was too late, as the D-backs offense could not do much against Scott Baker and a pair of Twins relievers.

Baker (3-2) allowed just one run on seven hits over six innings.

"They said the ball was getting on them a little quicker than the velocities," Melvin said. "He had kind of an unpredictable breaking ball that was hard to track, changed speeds just well enough."

Reynolds accounted for both of the Arizona runs. He hit his 16th homer of the year off Baker to lead off the sixth and drove in a run in the eighth on a groundout.

All and all, a frustrating night for the D-backs and one that left Johnson at a loss.

"I've got nothing more to say, really," he said. "Just one bad inning."