NEW YORK -- Matt Harvey demanded the ball in the ninth inning of the Mets' biggest game in years, the biggest start of his career.

He got it. And once again in the World Series, Harvey did not get the result he hoped for.

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This time the Dark Knight had plenty of help in wasting a lead, and New York's season came to a sudden end early Monday with a 7-2, 12-inning loss to the Kansas City Royals in Game 5 of the best-of-seven series.

''Unfortunately, I couldn't finish what I started,'' Harvey said.

Daniel Murphy made another key error, and Jeurys Familia blew his third save chance of the World Series. The NL East champions' bats were silent as their surprising late-season run to their first postseason since 2006 was quashed by the crisper Royals.

''This hurt, There's no doubt about it,'' David Wright said. ''But when we look on this season, when we get a chance a few days from now, a few weeks from now, to sit down and reflect on what we did to get here, I think it's going to bring a smile to everybody's face.''

With fans chanting his name even before he took the mound for the first pitch, the 26-year-old Harvey looked as if he was determined to set aside all the controversy that seemed to follow him this season, his first after Tommy John surgery in late 2013.

No more September talk about innings limits that rankled the Mets' front office and fans, his social life or Instagram account.

Harvey was determined to carry his teammates back to Kansas City for Game 6 after failing to hold a two-run lead in the sixth inning of the Series opener.

''I wanted it bad,'' Harvey said.

He gave up just four singles in the first eight innings and used all four of his pitches to strike out the Royals' stingy lineup nine times, including three in both the fourth and fifth.

After striking out Mike Moustakas with a 98-mph fastball to end the fourth, he pumped a fist and gave a couple of euphoric shouts as he stomped off the mound.

Following Alex Rios' groundout to end the seventh, Harvey threw his hands in the air and implored his teammates, ''Let's Go!''

He stalked off the mound with a 2-0 lead at the end of the eighth, having thrown 102 pitches. After talking to pitching coach Dan Warthen, he rushed to Terry Collins and implored his manager to let him finish for just the second complete game of his big-league career.

''I said, `Matt, you've got us exactly where we wanted to get you.' He said, `I want this game in the worst way.' So obviously I let my heart get in the way of my gut,'' Collins said. ''It was my fault.''

Said Harvey: ''I think there's a lot of fingers that you can point at, but I wanted the ball, and in that situation I did what I could to go back out there. ... I wanted the ball and obviously he wanted to go to Familia there but the way the game was going, the way I felt, I felt like I wanted to take control of the game and go back out there for the ninth.''

Harvey long ago blew past the 180 innings he and agent Scott Boras said Dr. James Andrews recommended as his limit after surgery. His 217th inning was one too many.

Harvey sprinted out to the mound in the ninth, then walked Lorenzo Cain and gave up an RBI double to - who else? - Eric Hosmer. Harvey stoically walked off the mound as Familia jogged in from the bullpen.

The Royals' put the ball in play against the Mets' beleaguered closer, and New York's defense botched one more late chance as Kansas City overcame another postseason deficit.

Wright fielded Salvador Perez's broken-bat chopper and made a one-hop throw to Lucas Duda for the out at first base. But Hosmer made a daring sprint home, and Duda's throw was way off target as the Hosmer slid headfirst into home plate with the tying run.

The Mets fell apart in the 12th. Addison Reed gave up the go-ahead run, then Murphy botched another play that left fans gasping for a second straight night and broke open the inning.

''There's just is no lead that's safe with these guys, especially one or two-run leads,'' Wright said. ''You know they're going to make a run. It's not a matter of if, it's a matter of when, and they did it again today.''