(AP) -- For a month, most everything Daniel Murphy touched seemed to turn out great for the New York Mets.

It's what he didn't touch -- or barely nicked, at best -- that dearly cost him and his team in Game 4 of the World Series.

The second baseman let a grounder get under his glove in the eighth inning and the Kansas City Royals quickly pounced for three runs, beating the Mets 5-3 Saturday night to take a 3-1 lead.

"There's no way to describe it. It hurts when you feel like you got a direct hand in a ballgame," Murphy said.

"I didn't do the job. That's the most frustrating thing," he said.

Murphy came into the World Series on a tear, having homered in a record six straight postseason games. The NL Championship Series MVP had also made every play in the field, belying his reputation as a boxy fielder and boosting his value as a free agent-to-be.

Since then, Murphy has severely struggled. He's just 3 for 17 at the plate, with only singles.

The error, though, that really wrecked him and the Mets.

Down 3-2, the Royals put runners on first and second with two outs in the eighth. After closer Jeurys Familia relieved, Eric Hosmer hit a chopper toward a charging Murphy -- it was hit too slowly for a double play, and his lone option was getting one out at first.

Instead, his glove came up and the ball stayed down. The sellout crowd at Citi Field gasped as it rolled into right field as Ben Zobrist raced home with the tying run.

Mike Moustakas followed with a go-ahead single and, with the fans sitting in stunned silence, Salvador Perez singled for an insurance run.

"It's part of the game," Familia said. "For me, I just try to be focused, try to get another groundball, try to forget. Because Murphy, he's one of the best players we have here."

"It just happens," he said.

Rather than evening the Series, the Mets now need to win three in a row.

"We're down 3-1," Murphy said. "We've got to get ready for tomorrow. I know it's cliche, but we've been in every game. The mistakes like the mistake I made tonight? That's a good club and they make you pay for it. I wish I would've caught it."

Murphy got a hit in the ninth but with two on, Lucas Duda hit a soft liner that Moustakas caught, and the third baseman's throw across the diamond doubled off Yoenis Cespedes to end it.

"Daniel Murphy didn't lose this for us. This was a collective team loss," Mets third baseman David Wright said. "There was dozens of things we could've done better in this game to win this game. They way that Daniel Murphy's been playing, the way that he's put this offense on his back at times, Daniel Murphy did not lose this game. We lost this game as a team."