CHICAGO -- It was as if the iconic ivy vines covering the bricks at this perfect little patch of green had come to life, unwilling to stomach the sight of Cubs rightfielder Jorge Soler, lying face down to the gleaming grass, helpless. Yes, Wrigley Field had picked a fine time to go from observer to participant.

In the sixth inning Tuesday night, with the Mets thinking they had tacked on a crucial insurance run, the ivy swallowed Wilmer Flores' sure RBI triple to the wall, a line drive that got past the diving Soler. Per ground rules that could only exist here, Flores was awarded only a double and Michael Conforto was sent back to third base, even though he could have scored from first on all fours with a billy goat strapped to his back.

Just maybe it would be the break the Cubs needed to turn the tide of Game 3 of the NLCS. But not even fate could derail the Mets, whose 5-2 victory moved them just one win away from a sweep and their first pennant in 15 years.

Daniel Murphy continued the run of his life, hitting his sixth postseason homer, a career franchise record. Jacob deGrom weathered early trouble to hold the Cubs to two runs in seven innings.

And the Cubs squandered their lucky break, surrendering a pair of insurance runs in the seventh behind two sloppy defensive plays. Now, to reach their first World Series since 1945, they must complete the near-impossible task of winning four straight games.

A boisterous crowd of 42,231 stuffed into the friendly confines were hoping that the Mets might finally blink. Two days before, manager Joe Maddon blasted music from the movie "Rocky," hoping to infuse an underdog's heart in his Cubs. As they lined up for introductions, the familiar theme blared from the loudspeakers. Through five innings, the Cubs had kept it close, wrestling the Mets to a 2-2 tie.

Yoenis Cespedes' first-inning double off Kyle Hendricks scored David Wright, who had lashed the first of his three hits this night. Murphy gave the Mets their second run in the third, when his solo shot off Hendricks settled into the centerfield bleachers above the bricks.

But the Cubs got homers off deGrom from Kyle Schwarber and from Soler.

The Mets pushed ahead 3-2 in the sixth thanks to a daring steal of third by Cespedes and a wild pitch from Trevor Cahill that Miguel Montero failed to block. The pitch struck out Conforto but bounced away, allowing Cespedes to score.

Wrigley's ivy then came to life. Flores ripped a two-out shot past Soler, whose ill-fated attempt at a diving catch left him helpless. The ball bounded to the wall and lodged into the ivy.

Centerfielder Dexter Fowler alertly extended his arms, a signal to the umpires that the ball should be ruled dead. Terry Collins protested, but the ground rules were clear. Flores was awarded a double and Conforto went back to third, where he was stranded.

The Cubs had life until the seventh brought doom. The Mets scored twice more, with some help. With one out and Wright on second, Murphy hit a roller to third baseman Kris Bryant, who double-clutched. The hesitation allowed Murphy to beat the throw.

Cespedes lifted a fly ball to left that Schwarber dropped, and Wright scored from third. One batter later, Murphy scored from third on Lucas Duda's groundout. The throw from first baseman Anthony Rizzo had come on a line. But Murphy's slide beat the tag. Through a cloud of dust, he pumped his fist and held the pose.