Clarke Schmidt made a mistake, and a familiar, dejected murmur spread through the ballpark.
Schmidt had surrendered a three-run home run and the Yankees had fallen behind by two runs in the top of the fourth inning.
And any deficit feels debilitating these days.
But as the Yankees try to launch a comeback in their season, Billy McKinney led a comeback Friday night.
McKinney responded with a three-run homer of his own in the bottom of the fourth, and both his bat and glove starred in a 5-4, series-opening win over the Royals in front of a sellout crowd of 46,242 in The Bronx.
The center fielder, who had been slumping, made two remarkable catches and hit his first homer in 15 games, giving the Yankees a lead they held, if narrowly.
McKinney’s was one of three home runs for the Yankees, who had scored seven total runs in suffering a three-game sweep in Anaheim earlier in the week.
With the win, the Yankees (51-47) snapped a four-game losing streak and awoke from their nightmarish, 1-5 road trip.
After two more games against the dreadful Royals (28-71) the disappointing Mets will come to Yankee Stadium on Tuesday and Wednesday.
As poorly as the Yankees have played, it is not too difficult to envision a run coming at home against subpar competition.
A surge also would be easier to envision if McKinney has found his stroke again.
The center fielder was brilliant upon being called up in early June and was hitting .320 after his 15th game.
But a deep slump (corresponding with a deep slump by virtually all the offense) followed, and he entered Friday 3-for-29 in his past 14 games.
McKinney stepped to the plate in the fourth inning at a quiet Stadium, shortly after Schmidt had coughed up a 1-0 Yankees lead by allowing a three-run homer to Michael Massey.
With two out, DJ LeMahieu had walked and Anthony Volpe had singled.
McKinney followed by hammering a first-pitch curveball from Alec Marsh over the right-field wall to give the Yankees a 4-3 lead and provide a semblance of hope for a flailing offense.
Franchy Cordero’s second-inning home run had given the Yankees their 1-0 lead.
Gleyber Torres’ 15th homer of the season, in the fifth inning, added some breathing room and a 5-3 lead.
The Yankees needed that breathing room because Tommy Kahnle served up a second home run to Massey, who drove in all four Royals runs, in the eighth inning.
Clay Holmes recorded his 12th save, but also provided some anxious moments in the ninth inning.
Drew Waters singled, then stole second base with one out before Maikel Garcia lined out. With two out, Bobby Witt Jr. hit a ground ball into the hole at shortstop.
Anthony Volpe backhanded the ball and threw to third — and a replay review determined that LeMahieu had applied the tag just in time.
The Yankees hung on to their edge thanks to clutch pitching and some excellent fielding from McKinney.
With the Royals trailing 5-3, Waters led off the seventh inning by blasting a Wandy Peralta changeup an estimated 393 feet to center.
McKinney gave chase, leaped in stride at the wall and caught it at his peak, robbing perhaps a home run and at least extra bases.
It was his second tremendous catch of the game.
He also robbed Kyle Isbel of at least a single with a sliding catch in the left-center gap to end the third inning.
The Yankees’ defense and pitching kept Kansas City from completing a comeback of its own, but the Royals helped, too.
Kansas City was down one in the fifth when Schmidt and the Yankees caught a significant break.
Isbel hit a double over Anthony Rizzo’s head with one out and Nick Pratto on first.
Giancarlo Stanton could not field it cleanly in the right-field corner, and Pratto could have sailed home — but he held at third.
Schmidt, given a second chance, stranded the runners.
He got Garcia to ground out and struck out Witt, then pumped his fist as he walked off the mound.
An inning later, the Royals put runners on the corners with two out when Schmidt, who had allowed three runs in 5 ²/₃ innings, was pulled for Peralta.
The reliable lefty broke Pratto’s bat on a fly out to escape.
The Yankees’ bullpen held the lead, just barely, that McKinney created.
With his bat and his glove, the center fielder showed a pulse, which allowed the slumping club to begin dreaming of a comeback greater than one game.
