Nationals starting pitcher Gio Gonzalez was perfect through five innings against the Cubs before giving up an infield single by catcher Dioner Navarro. (Nick Wass/Associated Press)

The Washington Nationals had the Chicago Cubs in an ideal position on Sunday. Starting pitcher Gio Gonzalez had carved through Chicago’s meager lineup, carrying a bid for a perfect game into the sixth inning. The Nationals gave him a 1-0 lead and he tossed seven dominating innings. With a low pitch count, he was poised to pitch deeper.

But with his spot in the order up first in the bottom of the seventh, Nationals Manager Davey Johnson turned to a pinch hitter. Setup reliever Drew Storen allowed the Cubs to tie the score with two outs in the eighth. And after Rafael Soriano surrendered two singles in the ninth inning, a wild throw by catcher Kurt Suzuki let in the winning run. A promising start by Gonzalez and the Nationals ended in head-scratching fashion, a 2-1 defeat and a series loss to the Cubs.

Johnson lifted Gonzalez after 86 pitches because he sensed an opportunity to tack on runs. The Nationals had put two runners on base the previous inning and he saw an opening in the seventh. Johnson sent his most veteran pinch hitter, Chad Tracy, to the plate. The bullpen was well-rested. Johnson weighed Gonzalez’s inconsistency in recent starts. He didn’t want to yank Gonzalez in the middle of the eighth should he put a runner on base.

“I don’t want him to lose the ballgame late in the game,” Johnson said. “Just the way I manage. Chalk it up to me. You don’t like it? Chalk it up to me. Didn’t work out.”

In the eighth, Storen coughed up a leadoff single to Cubs catcher Dioner Navarro, the same hitter who broke up Gonzalez’s bid at a perfect game. Navarro was lifted for a pinch runner, starting pitcher Travis Wood. A sacrifice bunt moved Wood to second. He tagged up and took third base on a popup caught in foul territory by Nationals first baseman Adam LaRoche. A chop single by Starlin Castro on a slider over the plate tied the game at 1.

“I thought I made good pitches and you gotta get the first guy out,” Storen said. “You do that, you have no problems.”

In the ninth, Soriano, the Nationals’ best reliever of late, was asked to keep the score tied. Instead, Alfonso Soriano led off with a weak single to left. Julio Borbon followed with a single to center. With one out and the Nationals’ closer facing Welington Castillo, the Cubs attempted a double steal.

Suzuki caught a high fastball, hopped to his feet and fired toward third base. The throw slightly grazed Castillo’s bat and went wide of third base and rolled to the wall in foul territory. The winning run scored on what was officially ruled an error. The Nationals have 30 errors on the season, second only to the Cubs’ major league-leading 31. “It was bad luck, bad day,” Rafael Soriano said.

Suzuki watched in disbelief after the throw. Johnson emerged from the dugout to check with home plate umpire John Tumpane. There wasn’t any interference by Castillo because he held his ground in the batter’s box.

“When I work on that, I don’t work on clearing the bat,” Suzuki said. “I just make sure I don’t hit the guy in the head and obviously I didn’t hit him in the head with the baseball so I did my job, just I threw it and it hit the bat.”

For seven innings, Gonzalez mowed through the Cubs’ lineup, a prospect of a no-hitter looming through five against a team hitting .219 on the road and a lineup with four hitters carrying sub-.200 averages. Navarro, a catcher generously listed at 205 pounds, broke up Gonzalez’s perfect game with an infield single when he rolled over a sinker, hitting it deep into the hole where shortstop Ian Desmond couldn’t make a play.

Gonzalez’s only struggle came after the hit. After two quick outs, he walked Castro and Cody Ransom loaded the bases with a single to left. Gonzalez got No. 3 hitter Anthony Rizzo to ground out to LaRoche to end the inning. Gonzalez would log one more inning, an easy 1-2-3 seventh, until Johnson turned to a pinch hitter and Storen. A weak offensive output from the Nationals’ lineup gave Gonzalez little room for error.

“I trust my bullpen100 percent and trust our offense 100 percent,” Gonzalez said. “I don’t question Davey’s job. He’s a great manager and knows what he’s doing. Again, it was one of those tough situations.”

The Nationals whiffed at their most fruitful opportunity of the game against Cubs starter Scott Feldman and his shaky command in the first inning. Denard Span doubled to center to lead off the game. Bryce Harper, back after missing two games following a procedure to remove a troublesome ingrown toenail, walked. Ryan Zimmerman then doubled off the out-of-town scoreboard in right field to plate Span. With two outs, Desmond drew a walk to load the bases.

But Danny Espinosa lifted an outside 1-1 sinker off the end of his bat to left field, a flyball that Alfonso Soriano tracked down for the inning-ending out. The Nationals sent seven batters to the plate but managed only one run. Feldman allowed only three more hits over the next five innings. He, like Gonzalez, had the benefit of Tumpane’s generous strike zone.

Following the loss, the Nationals were upbeat but clearly frustrated that a winnable game slipped away.

“I’m not gonna put this all on Gio,” Johnson said. “These guys can do it. We didn’t do it. But we’re fully capable of doing it. And it’s a long season. We can get things going our way. But I have [all the] confidence in the world that Storen could hold them right there and Soriano [could] close out the ninth.”