NEW YORK -- Hours before the New York Mets enjoyed their most productive showing in nearly five years, manager Terry Collins challenged the team to step it up.

The numbers he threw out in the private meeting might not necessarily have been 15 and 21 but those were the magic figures for his offensively challenged team.

As in 15 runs and 21 hits.

The Mets reached both totals, getting four hits apiece from rookie left fielder Michael Conforto and center fielder Kirk Nieuwenhuis in a 15-2 rout of the Los Angeles Dodgers Saturday night.

Long before the Mets reached 21 hits for the first time since Sept. 5, 2010 at the Chicago Cubs and came within one of the 1981 club record for hits in a home game, Collins told the team that playing time would be based on who is hitting well.

"I just think it was a night that they came out and knew they had to swing the bats and we got huge hits," Collins said. "We just found holes which you got to do and later on we hit the ball hard. As I said, we're looking at 60 games and it's time to pick up the pace."

After getting outscored 10-2 in the first two games against the Dodgers, everybody hit well for the Mets, who reached their most runs since getting 16 on April 12, 2013 at Minnesota.

Conforto and Nieuwenhuis had hits in their first four at-bats as they combined to go 8-for-8 with five RBI and six runs scored.

A night after going 0-for-3 with an RBI groundout in his major league debut, Conforto began his big night with an RBI infield single during a four-run first inning off right-hander Zach Lee (0-1), who attempted to make a play before it deflected off his glove. With his father, aunt and uncle in the stands, Conforto added doubles in the third and fifth before singling in the sixth.

Conforto became the first Met to get a four-hit game before his third career game and the fifth player in the last century to score four or more runs in one of his first two games.

"I was eager to come out today and get that first one out of the way," Conforto said. "I got a little lucky on the first one and that took a little load off and I could just relax. It was really fun."

Nieuwenhuis began the night with a .167 average but when his second career four-hit game ended, it climbed to .214. He began with a two-run single in the first, added an RBI double in the third and a run-scoring double in the fifth before getting an RBI single in New York's five-run sixth.

Conforto and Nieuwenhuis were among seven starters with at least two hits for the Mets, who were held to nine hits in their first 18 innings against Los Angeles.

"A lot more fun than it was yesterday and the day before," Nieuwenhuis said. "It's great. It's just a good reminder that baseball's a crazy game and you can't get too caught up in some of these tough stretches."

Second baseman Kelly Johnson made his debut after being acquired from Atlanta and hit a solo home run in the fourth inning. Third baseman Daniel Murphy opened the scoring with an RBI single and then blasted a two-run shot in the sixth.

Slumping first baseman Lucas Duda added a pair of solo home runs in consecutive at-bats and New York hit four home runs for the fifth time.

"We had one those nights where the team couldn't miss," Johnson said.

Even right-hander Matt Harvey (9-7) joined in offensively with two RBI for the third straight start. Besides getting an RBI double and run-scoring single in consecutive at-bats, Harvey allowed solo home runs to shortstop Jimmy Rollins and center fielder Joc Pederson among six hits in seven innings.

"For us today was a big win and obviously everybody contributed," Harvey said. "I think that was a huge team win for us and we were definitely happy."

New York was 9-for-16 with runners in scoring position and even scored twice without making contact.

Nieuwenhuis scored the final run of the sixth when right fielder Curtis Granderson struck out and reached on a wild pitch and in the seventh pinch hitter Eric Campbell drew a bases-loaded walk.

Lee became the Dodgers' 14th different starting pitcher of the season after being recalled from Triple-A Oklahoma City before the game. In his major-league debut, he lasted 4 2/3 innings and allowed seven runs and 11 hits, marking the first time in 30 games a Los Angeles starter allowed more than four earned runs.

"That's kind of me trying to be too much of an athlete sometimes," Lee said of Conforto's infield hit. "Not necessarily knowing what the defense is behind me. I let that ball go, we're out of that inning with probably one run, hopefully we get a double play on that ball and limit the damage."

Los Angeles fell to 5-4 on its 10-game trip that concludes with right-hander Zack Greinke returning from paternity leave Sunday. The Dodgers allowed season highs in runs and hits and also allowed their most runs ever against the Mets.

"They didn't really miss pitches," Rollins said. "They were barreled loud,"

NOTES: Because the Mets believe the acquisition of INFs Kelly Johnson and Juan Uribe gives them more options, manager Terry Collins said INFs Wilmer Flores and Daniel Murphy will take ground balls at shortstop and second base, respectively. Collins also stressed that playing time is based on performance, which he also reiterated to the team privately. ... Los Angeles 1B Adrian Gonzalez was out of the original lineup due to neck stiffness but after getting through batting practice, he wound up starting. ... New York GM Sandy Alderson addressed the media for a third straight day and was asked if there will be more trades. "We continue to look at all the possibilities and how those different possibilities would fit right now. ... Los Angeles LHP Ian Thomas was optioned to Triple-A Oklahoma City after allowing a run and three hits over five innings Friday.