That the D-backs came out on the wrong end of a 5-4 decision to the Giants was more a reflection of their defense than of the performance of their 44-year-old left-hander.
"That's why we lost tonight, we kicked it around," D-backs manager Bob Melvin said. "We didn't make the plays when we had to. When you play defensively like we did tonight and it's a close game, it's going to cost you and it cost us tonight."
Boy, did it ever.
Errors by third baseman Mark Reynolds and shortstop Stephen Drew played a part in the five Giants runs, all of which were unearned.
Johnson, making his first start since June 28 of last year, showed no ill effects from his August back surgery. So while his performance wasn't necessarily a work of art, it was definitely an encouraging one.
"My endurance was fine," said Johnson, who threw 90 pitches. "I didn't get tired or anything. Everything feels good on my body."
Early on in the game, Johnson struggled with his command, particularly on his two-seam fastball to right-handers. That could have been in part because of the mound at AT&T Park, which according to several players was too high and is not sloped properly.
"It's a joke," Melvin said of the mound. "Both teams have to play on it, but it takes a little adjustment period to get used to it. It's not an excuse, because both teams are pitching off the same mound."
Johnson walked four in his five-inning stint, and it might have been more if not for his secondary pitches. While scuffling for fastball command, Johnson was able to rely on his slider and split to keep the San Francisco hitters guessing. Of the 20 sliders he threw during the game, 18 went for strikes.
"That's going to get better, without question," pitching coach Bryan Price said. "That's a guarantee that his command and ability to pitch ahead is going to get better. He had really good stuff. Even though he was frustrated the first few innings, I was very pleased with his overall performance."
The D-backs spotted Johnson an early lead thanks to Conor Jackson's two-run homer in the first inning.
The Giants scored three runs in the second thanks to Reynolds' misplay of a Jose Castillo grounder. Even with the error, Johnson was close to getting out of the inning, but Randy Winn's blooper to shallow left hit in and out of the glove of a diving Drew and a pair of runs scored.
A two-run third inning put the D-backs back in the lead at 4-3 and Johnson seemed to find his rhythm as he limited the Giants to one hit and one walk in his final three innings and departed with a 4-3 lead. The final batter he faced, Bengie Molina, popped up to second.
"He dominated me," Molina said. "So I think he looked pretty good."
"I got a lot of room for improvement," Johnson said. "But considering the situation and all that, I know that things will get a lot better. I typically don't walk a lot of hitters like that. I felt like I was battling out there, finding myself behind in the count."
Still, when he departed the game, the D-backs were ahead and Johnson was in line to pick up career win No. 285.
Johnson will have to wait at least another five days for that as the defense once again did not get the job done in what proved to be the decisive seventh.
Pinch-hitter Eugenio Velez led off by beating out an infield single, but it looked like Arizona reliever Chad Qualls had a double play when Winn hit a bullet right at Drew. But the ball scooted under Drew's glove and the Giants wound up scoring twice.
"If the game's pitched a little bit better by myself early in the game, the outcome is probably not what it was," Johnson said.
Maybe not, but if the D-backs play better defense the outcome certainly would have been different.
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.