The throw goes wide of Ryan Zimmerman as Arizona’s Paul Goldschmidt steals third base during the second inning. (Matt York/Associated Press)

The Washington Nationals’ winning streak ended Sunday afternoon without equivocation. They could do no wrong for a week, and then almost nothing went right. The Nationals’ defense briefly imploded, their starter couldn’t last five innings and their bats, at least for the first six innings, turned to dust. The best record in the majors worsened by a game. So things could be worse for them.

The Arizona Diamondbacks halted the Nationals’ blitz at eight games with a 7-4 victory at Chase Field. As Ross Detwiler fought through stomach illness and sinus issues, Diamondbacks rookie starter Patrick Corbin faced the minimum through the first six innings. Arizona took a seven-run lead after five innings after battering reliever Craig Stammen. By the latter innings, Manager Davey Johnson started pulling his regulars.

“As much as I wish, we weren’t going to win every game the rest of the season,” third baseman Ryan Zimmerman said. “We’re going to lose just like everyone loses. You know, we won the series.”

After they foundered most of the afternoon, the Nationals still managed to get the tying run to the plate in the ninth inning. After a leadoff single by Cesar Izturis and missiles off the wall by Michael Morse and Tyler Moore, the Nationals scored two runs and forced Arizona to call on closer J.J. Putz with one out. Steve Lombardozzi drew a two-out walk to bring Roger Bernadina to the plate with two on. Bernadina struck out, and the Nationals had to contemplate starting a new win streak.

The mostly ugly day provided a blip in one of the best sustained stretches of baseball since baseball returned to D.C. The Nationals had won 12 of their previous 13 games on the road. They will still head to San Francisco with a 71-44 record, 6-1 on their current trip.

“Any time you lose, it stinks, no matter what,” said catcher Kurt Suzuki, whom the Nationals traded for on Aug. 4. “But I mean, that’s the first time I lost here.”

They were of course bound to lose at some point. The loss didn’t have to be quite so thorough.

Detwiler only yielded three hits and a walk during his 42 / 3 innings, but he lacked the sharpness from his past two starts, when he allowed two earned runs in 14 total innings. When he arrived at Chase Field, Johnson knew it would be a difficult day. Detwiler had trouble keeping food down, and rubbed the bridge of his nose to try to alleviate sinus pain.

Throughout his start, Detwiler took deep breaths on the mound. After the fourth inning, Johnson said, he could hardly stand in the dugout. He still went out for the fifth.

“He was really under the weather before he even started the game,” Johnson said. “You could tell by his mannerisms he didn’t feel right. He was all messed up. He gutted it out, though, for us.”

Detwiler refused to blame his performance on his health. He declined to provide details about his condition, to avoid making it an excuse.

“I just didn’t execute my pitches today,” Detwiler said. “The pitches were all up. They were able to get the barrel on it and not leave anything on the ground. If I’m feeling bad and I still get my pitches down, then I get outs. I don’t think that’s the excuse why I did bad at all.”

In his past two starts, Detwiler had relied on fastballs low in the strike zone, pumping his sinker more than he used his four-seam fastball, which zips straighter and harder. Sunday in the desert, the approach did not transfer. Of the 21 batters Detwiler faced, 12 hit a line drive or a flyball, his highest total in a start this season. Enough of them found gaps.

“I could tell early I wasn’t getting my pitches down,” Detwiler said. “I was kind of fighting myself all day.”

First, his defense betrayed him. Paul Goldschmidt led off the second inning with a grounder to third. Zimmerman made a spinning stop and lobbed a throw across the diamond that skipped past Adam LaRoche at first.

“Just a bad throw,” Zimmerman said.

Goldschmidt moved to second. On Detwiler’s first pitch to the next batter, he dashed for third base. Suzuki rifled a throw wide to the right and into left field. Goldschmidt scooted home with a run the Nationals had gifted him.

Detwiler’s day ended in the fifth. With one out, he walked Chris Young and yielded a booming double to Aaron Hill. Jason Kubel ripped a line drive back at his face, which Detwiler caught out of self-preservation.

Detwiler had reached 93 pitches, and Johnson did not want him facing right-handed masher Justin Upton. Stammen jogged in from the bullpen and turned a 4-0 game into a blowout. Goldschmidt, Upton and Miguel Montero greeted him with a single up the middle and two smashed doubles, scoring three runs. They moved ahead 7-0, and the Nationals’ winning streak moved to life support.

After their offense had scored more than five runs per game in August, the Nationals managed five hits. Bryce Harper chopped an infield single in the first, which Goldschmidt could have erased if he scooped a throw in the dirt at first base. Then Harper got picked off, and Corbin, a lefty who entered with a 3.53 ERA, retired the next 16 batters he faced. The Nationals came within one low throw of staring at a possible perfect game.

“He’s pretty good,” Suzuki said. “He definitely keeps the ball out of the middle of the plate, works down in the zone with a two-seamer and works in and out. For a young kid to have that kind of command, he did well.”

The Nationals eliminated any possible controversy in the seventh, scoring two runs after Danny Espinosa led off with a double and Zimmerman lined a single to left. By then, the runs were window dressing. Johnson replaced Zimmerman with backup infielder Izturis.

The Nationals retreated to their clubhouse and packed for the West Coast in near silence, no celebratory music or backslapping, a scene the Nationals had not played out for some time. “It was a little different,” Suzuki said.