James Shields screamed into his glove and then tore the black leather off his left hand, the act of a man who wished baseball came equipped with either a rewind button or a hole by the pitcher’s mound large enough to crawl into and hide. One half of one inning of the 110th World Series had elapsed, and Shields, the player who bridged the Kansas City Royals’ irrelevance and eminence perhaps more than any other, already resembled a beaten man.

This city waited three decades to host the World Series, and in the matter of minutes it watched as the Royals’ rampage through the American League playoffs went splat Tuesday night in a 7-1 Game 1 loss. Once the top of the San Francisco Giants’ lineup pummeled Shields, they handed the ball to Madison Bumgarner, the 25-year-old left-hander with a pterodactyl’s wingspan and a warden’s disposition. Shields’s misery yielded to Bumgarner’s mastery. He allowed one run in seven three-hit innings and retired 12 in a row at one point. Before Salvador Perez’s solo homer in the seventh inning, Bumgarner had opened his World Series career with 212 / 3 scoreless innings.

The outcome formed in an instant, ordained once Shields allowed three runs in the first inning, two of them on Hunter Pence’s rocket over the center field fence. The outburst meant Bumgarner pitching in the World Series with a lead, which meant deflation sweeping down boulevards, past fountains and across the Plaza. Shields gave Bumgarner an opening, and Bumgarner suffocated the Royals, ending Kansas City’s postseason winning streak at eight.

“We got too much heart in this clubhouse,” Shields said. “We’re not worried about that right now.”

Rebounding from losses happens 60 times a summer even for the greatest teams. It is part of the game’s natural order. But for the Royals, it may actually provide a challenge. Staggered now, they had not lost since Sept. 27. How will they respond?

No stranger to late October baseball, Giants third baseman Pablo Sandoval — already a World Series MVP, back in 2012 — goes 2 for 5 with two RBI as the Giants roll in Game 1. (Matt Slocum/Associated Press)

“I couldn’t answer that, because this is our first time losing in postseason,” Royals third baseman Mike Moustakas said. “I can speak for everybody in this clubhouse — we’re not worried about it. We’re not concerned. We’re not happy that we lost, but we get another game tomorrow.”

Downtown Tuesday morning looked like a college campus on a fall Saturday, everyone decked out in team colors, interlocking KCs on hats and cursive “Royals” across chests. The city had been electrified as its baseball team grew invincible. They waved towels and screamed half an hour before first pitch. During Giants introductions, fans eschewed boos for deafening chants of “Let’s Go Roy-als!”

The Royals had floated into the World Series by means both miraculous and impressive. They staved off elimination in the wild-card game after they trailed the Oakland A’s, 7-3, in the eighth inning. Their irrepressible athleticism and monstrous bullpen overwhelmed the Los Angeles Angels and Baltimore Orioles. Their ace walked to the mound to start the Series.

Kansas City announced itself as an ascendant contender in December 2012, when it dealt top prospect Wil Myers and others for Shields and Wade Davis. Shields became the final piece of a team built through drafting and small free agent splashes. He helmed their staff, starting the wild-card game and Game 1 of the ALCS. They wanted to give him the ball.

In Kansas City’s first World Series game since 1985, Shields threw batting practice. Amidst a frenzied crowd, center fielder Gregor Blanco led off with a line-drive single to center field. Buster Posey ripped another single. Pablo Sandoval golfed an RBI into the right field corner. A relay throw to the plate nailed Posey and bailed out Shields, but only temporarily. Hunter Pence dug in to the right-handed batter’s box, wild-eyed and elastic-limbed.

“My mind went to two outs, runner on second,” Pence said. “Do what you have to get him in.”

He swung through a fastball to make the count 2-2. He took one 94-mph fastball to run the count full and fouled off another, Shields unable to finish him off. Shields fired another fastball, belt high and over the plate’s heart. Pence destroyed it. The Giants led 3-0, and the park’s noise was reduced to murmurs.

SungWoo Lee, a Royals super fan from Korea, threw out the first pitch at the Aug. 11 game against the Oakland Athletics, which the Royals won 3-2. (Doug Bryan)

“Probably just over-throwing, maybe amped up a little bit,” Shields said. “I got to bear down and get the job right there. That’s the bottom line. I didn’t get the job done. Hopefully, I get another start.”

Manager Ned Yost confirmed Shields would start Game 5, but Game 1 was unkind. Shields survived a torrent of loud outs in the second and third innings, but he couldn’t escape the fourth. Pence smoked a double down the left field line, Shields walked Brandon Belt and former Washington National Michael Morse roped a single to center. He pumped his fist as Pence motored home.

Yost emerged from the dugout and pointed at the bullpen. Shields stood on the rubber and stared at Yost, ball in glove and glove on hip, as if he could not believe the sight of his manager coming to get him. In 295 career starts in both the playoffs and regular season, Shields had exited without recording an out past the third inning twice. Game 1 of the World Series made three.

“He’s been the guy for us all year,” first baseman Eric Hosmer said. “They got to him. That’s it.”

The first batter reliever Danny Duffy faced was Juan Perez, a defensive replacement who entered the game in the fourth inning. Giants Manager Bruce Bochy knew Bumgarner had all the runs he required. Bumgarner escaped the only trouble he found, a no-out, second-and-third jam he escaped by striking out two in the third inning. With the bases loaded and two outs, Hosmer grounded a first-pitch slider to second.

“It changes everything,” Hosmer said. “You cash in there, you get right back in the game. The crowd is back into it. Everyone is back into it.”

The Giants are now 16-2 in their past 18 postseason games, and they stand three victories away from their third World Series championship in five years. Shields is in good company, because the Giants have also won games this postseason started by Stephen Strasburg, Jordan Zimmermann, Gio Gonzalez, Adam Wainwright and Shelby Miller.

“These guys, they just know how to play in this situation,” said Steve Balboni, a slugging hero on the 1985 Royals and now a Giants scout. “They play with high energy, high adrenaline and relax at the same time. They perform to their very best. You look at them during the season, it’s not the same.”

The last team to sweep through the first two rounds of the playoffs, the 2007 Colorado Rockies, lost Game 1, 13-1, and was swept out of the World Series. The Royals will attempt to avoid the same fate starting with right-hander Yordano Ventura, a 23-year-old rookie with a 100-mph fastball, in Game 2 on Wednesday night.

“He has no fear,” Shields said.

The Royals have proven this October they cannot be counted out. But now they face an opponent that has proven over several Octobers that it, perhaps, cannot be beaten this time of year. They will don blue again Wednesday in Kansas City, but they no longer feel quite so invincible.