NEW YORK -- Third baseman Mike Moustakas' tie-breaking RBI single highlighted a three-run eighth inning Saturday night that lifted the Kansas City Royals to a 5-3 win over the New York Mets in Game 4 of the World Series at Citi Field.

The Royals came back from deficits of 2-0 and 3-1 to take a commanding three games to one Series lead. Kansas City will look to clinch its first championship since 1985 on Sunday, when right-hander Edinson Volquez is scheduled to face Mets right-hander Matt Harvey at Citi Field.

The Mets were five outs away from tying the Series when right-hander Tyler Clippard walked second baseman Ben Zobrist and centerfielder Lorenzo Cain. Right-hander Jeurys Familia, New York's closer, entered and induced first baseman Eric Hosmer to hit a slow grounder to second. But the ball went under the glove of Daniel Murphy and dribbled into shallow right field as Zobrist scored the tying run and Cain raced to third.

Moustakas followed with a single to right to score Cain and catcher Salvador Perez singled to right -- his third hit of the game -- to bring home Hosmer with an insurance run.

Right-hander Ryan Madson, the Royals' fourth pitcher, earned the win with a perfect seventh. Right-hander Wade Davis threw the final two innings and notched his first save of the Series and his fourth of the postseason. He allowed two hits in the ninth but got first baseman Lucas Duda to lineout into a game-ending double play.

Left fielder Alex Gordon had an RBI single in the fifth inning.

Rookie left fielder Michael Conforto hit two solo homers for the Mets. At 22 years old, Conforto is the youngest player to hit two homers in a World Series game since the Atlanta Braves Andruw Jones did it in Game 1 in 1996 against the New York Yankees.

Right fielder Curtis Granderson added a sacrifice fly.

Royals' right-hander Chris Young, who won Game 1 by throwing three hitless innings in Kansas City's 5-4, 14-inning victory, allowed two runs on two hits and one walk while striking out three.

Mets rookie left-hander Steven Matz, making his third postseason start and the ninth of his career overall, allowed two runs on seven hits and no walks while striking out five over five innings.

Young retired the first six batters before Conforto homered to right on the first pitch of the third. Shortstop Wilmer Flores then singled, took second on a wild pitch, went to third on a sacrifice by Matz and scored Granderson's fly to right.

The Royals cut the gap in half but used their best bench weapon in the fourth. Catcher Salvador Perez laced a one-out double and scored on Gordon's single. After right fielder Alex Rios flied out, Young was pinch-hit for by Kendrys Morales, who usually serves as Kansas City's designated hitter.

Morales singled, but Matz retired shortstop Alcides Escobar on a liner to right to end the threat.

Conforto then led off the bottom of the inning by homering off left-hander Danny Duffy. It was Conforto's first major league homer off a southpaw.

NOTES: Royals RHP Chris Young is the first pitcher to earn a win in relief and then make a start in the same World Series since Don Larsen did it for the New York Yankees in 1957. Larsen threw 7 1/3 innings of relief in Game 3 before starting Game 7 against the Milwaukee Braves. ... Royals RHP Edinson Volquez, who traveled home to the Dominican Republic after Game 1 to attend his father's funeral, was not back in New York before the game but is still in line to start Game 5 on Sunday. ... Mets SS Ruben Tejada, who suffered a broken leg when he was toppled over by Dodgers 2B Chase Utley in Game 2 of the NL Division Series, said Saturday he believed the slide was dirty but he is no longer mad about it. ... Mets RHP Noah Syndergaard, who scored in Game 3, is the first pitcher to score a run in a World Series game since Yankees LHP Andy Pettitte in Game 3 of the 2009 World Series.