Cubs beat Mets 5-1 to open three-game – wait, what?

This was the way it was scripted to look in the playoffs.

Maybe not 75 degrees at game time with the ivy in full green, but you get the idea.

Big-money lefty Jon Lester pitching 7 2/3 worthy innings against the Mets.

MVP candidate Anthony Rizzo fouling off pitch after pitch after pitch (after pitch after pitch) before hitting a game-turning three-run home run.

And the Cubs beating the Mets 5-1 in the opener of a series.

It was only July, but Monday night’s victory against the team that swept them in October – and again in four games two weeks ago in New York – looked more significant, if only for how much different this one looked than any of the previous eight these teams played.

If only for how emotionally wrecked and hapless the Cubs looked for four days in New York a week before the All-Star break.

If only for the fact they might need to beat these Mets in October to get where they plan to go, and it might help to know they’ve done it during this last three-game shot this week to do it during the season.

“Especially against them,” said Kris Bryant, who made five sharp plays at third – including a third-inning try for a triple play — on an errorless night for the fielders. “Losing seven [actually eight] in a row and then finally getting one is huge for us, just for the confidence going into the rest of the series, and just the rest of the second half.”

Until Monday, the Cubs had lost eight straight to the Mets, starting with last year’s National League Championship Series – the lineup averaging 2.4 runs and 10.1 strikeouts a game, the pitching staff with a 7.09 ERA during the skid.

On this night, Lester reversed a personal two-game slide that included a four-out, eight-run start in New York – including 11 of 12 at one point and 16 of 18 until a two-out single by the final batter he faced.

“Outstanding,” said manager Joe Maddon, who hasn’t used that word for more than a year when the Cubs faced their generations-old nemesis.

“We didn’t play very well in New York, and the biggest thing was we came out tonight and played clean baseball,” said Lester (10-4), who was the National League’s Pitcher of the Month for June before the mini-skid.

“I think that’s the key for us, just getting back to clean baseball with these guys [Mets].”

After losing 15 of 21 into the break, the Cubs have won three of four against American League West-leading Texas and the defending National League champs.

“They’re a good team. Their pitching staff’s the best in baseball,” Bryant said of the Mets. “Anytime you win a game against teams like that, the confidence goes up a little bit.”

Said catcher David Ross, who delivered a sacrifice fly in the sixth for a 4-0 lead: “They’ve had our number, but they caught us when we weren’t playing great ball. The big games come in September and October.”

The Cubs still await the return of leadoff man Dexter Fowler, the early season catalyst who has been sidelined by a hamstring injury for a month. Opening Day starter Jorge Soler also is sidelined by a hamstring injury, and starters Jason Heyward and Ben Zobrist got days off Monday.

But they beat the Mets primarily they same way they beat the Rangers in the weekend series: pitching.

The starting pitching that was the strength of the early season, and a problem spot during the 21-game skid into the break (6.04 ERA), is 3-1 with a 1.95 ERA since. And they’re averaging seven innings in those four starts.

Rizzo’s homer set a tone in the third inning, coming on the 10^th pitch of the at-bat against left-hander Steven Matz, an at-bat that Bryant called Rizzo’s best of the year.

“It was good to get a win against them,” Rizzo said, downplaying the importance. “The Mets are a good team. It’s nice we took the first game of the series and we have Jake [Arrieta] going [Tuesday].”

Until Lester’s gem, Rizzo’s home run, and the three-hit performance of Matt Szczur Monday, the Mets were the only opponent among the preseason favorites the Cubs had not played well this season.

“Obviously, everybody that comes in here, anybody that we play, we’ve got the target on our back,” Lester said. “They want to beat us. They’re going to give us their best. We know that.

“We’ve just got to go out and make sure that we don’t beat ourselves. We’ve done that prior to the break and been playing really good baseball after the break. Hopefully we’ll just continue to do that and keep pitching and work on the rest as we go.”