MLB

John Buck’s grand slam leads Mets to victory over Twins

MINNEAPOLIS — What the Buck?

While R.A. Dickey tries to figure out the American League, a spare part in last December’s mega-trade that sent the knuckleballer to Toronto has brought legitimacy to the Mets’ lineup, at least for the first 10 games of 2013.

John Buck’s pace will eventually slip, but the question is when. Friday night the veteran catcher hit a grand slam — his fourth homer in as many games — leading a 16-5 demolition of the Twins on the Frozen Tundra of Target Field.

With temperature at first pitch 34 degrees and flurries falling — after five inches of snow was removed from the ballpark on Thursday — the Mets convincingly snapped a two-game skid.

Buck’s fifth career grand slam — a laser into the mezzanine seats in left field in the second inning off Pedro Hernandez — gave Jon Niese an eight-run lead, a needed cushion on a night the lefty struggled with his command.

Buck, who has six homers and 19 RBIs to start the season, became the first Met since David Wright in June 2007 to hit a home run in four straight games.

“What streak?” Buck said, when asked about his recent tear. “I’m just benefitting from last year, when I tried too hard. Now I’m just going up there and trying to hit the ball solid and good things are happening.”

Buck has already eclipsed his career-best RBI total for a calendar month. His previous high was 17 in August 2004 with the Royals.

“You’re almost starting to take it for granted that when you need a big hit you’re going to get it [from Buck] and he’s going to drive in runs when he gets his hit,” manager Terry Collins said. “It’s just amazing: One night after the next, and while he’s hot you ride it.”

Daniel Murphy also had a huge night, finishing 4-for-5 with four RBIs. The four hits matched a career high. Wright finished with three hits and four RBIs, falling a home run short of the cycle.

Niese (2-0) pitched five innings and allowed five runs, four earned, on five hits with four walks and one strikeout. It snapped a streak of 22 consecutive starts by Niese in which he had lasted at least six innings. Niese said the cold weather affected his grip on the ball, to the point he stopped throwing his cutter.

“It was just tough to be consistent with [pitches],” Niese said. “Some pitches would feel good, and then a pitch later it would slip out of my fingers and the ball would hang there.”

Wright singled in a run in the second to give the Mets a 6-2 lead before Ike Davis walked to load the bases. Buck then unloaded on a full-count pitch, extending the Mets’ streak of games with a homer to begin the season. They are the only team in the major leagues to have homered in every game.

Marlon Byrd’s two-run single in the first inning against Vance Worley gave the Mets a 5-0 lead after third baseman Trevor Plouffe let a Buck grounder, a potential double play ball, roll through his legs for a run. Wright’s two-run double started the spree.

Collins said he had no problem with the decision to play. But he did seem concerned with a weather report it could be 17 degrees — with the wind chill — in Denver when the Mets play the Rockies on Wednesday.

“That’s cold — maybe too cold,” Collins said. “I mean, I grew up in Michigan. I played a lot of cold baseball games. I’m not sure I ever played when it was 17 degrees.”

If there was a saving grace for the players last night, there wasn’t much wind. Temperatures are expected to remain in the 30s and 40s for the remainder of the series.

“It’s cold, obviously, but it didn’t feel unbearable,” Murphy said. “But when the wind started blowing it was extremely unpleasant. If the wind stays quiet, it’s bearable.”

mpuma@nypost.com