Miami ? Sammy Sosa was livid as he argued with plate umpire Larry Poncino, certain that last pitch was ball four, not strike three.

Sosa gestured and fumed, but Poncino wasn’t budging. The slugger’s arguments weren’t any more successful than Chicago’s swings Sunday, leaving the Cubs still one win shy of their first World Series appearance since 1945.

Josh Beckett held the Cubs to just two hits and struck out 11 as the Florida Marlins beat Chicago, 4-0, in Game 5 of the NL championship series.

With the Cubs leading three games to two, the series now goes back to Wrigley Field, where ace Mark Prior will pitch Game 6 Tuesday night for Chicago.

“There’s nothing to be ashamed about, as far as I’m concerned, when a guy throws like that,” Cubs hitting coach Gary Matthews said. “We didn’t hit a lot of balls hard. Beckett had a lot to do with that.”

The Cubs’ offense was nearly unstoppable in the first four games, setting an NLCS record with 10 homers.

They hit .299 and outscored the Marlins 33-19.

Everyone was swinging the bat well. Aramis Ramirez had six RBIs Saturday, including the first grand slam by a Cubs player in the postseason.

Kenny Lofton had six straight hits, also an NLCS record.

And Sosa homered twice in the first four games, driving in five runs.

Cubs pitcher Carlos Zambrano reacts after allowing a two-run homer to Mike Lowell. The Cubs lost, 4-0, Sunday in Miami.

But against Beckett, the Cubs had trouble just getting on base. They put only three runners on, and no one got past first. They didn’t get a hit until Alex Gonzalez’s two-out single to right-center in the fifth.

It didn’t do much good, either, as Paul Bako flied out to center to end the inning.

“That,” Eric Karros said, “was probably the best pitching performance against us all year.”

Sosa was 0-for-4, and he had a rough day all around. Beckett buzzed him with a head-high heater in the fourth inning, sending the slugger sprawling backward.

He jumped up and shouted at Beckett and had to be calmed down by Marlins catcher Ivan Rodriguez. Sosa finally stepped back into the batter’s box, only to go down on a called strike three pitches later.

He didn’t like the call, either.

“We came to a tough park and won two out of three,” Sosa said. “Now we’re going back home, and we have to step forward.”

And the Cubs have to like their odds.

Since the NLCS went to a seven-game format in 1985, eight of the nine teams that took a 3-1 lead advanced to the World Series.

They’re returning to Wrigley Field, where they were 44-37 during the regular season and are 2-2 in the postseason. Most importantly, they will have their best pitchers going.

Prior will pitch Tuesday, and Kerry Wood will pitch Game 7, if necessary. The Cubs are 5-0 in the postseason when they pitch.

“For them to get through us, they’ve got to beat our best,” Matt Clement said.

Prior is 12-1 with a 1.55 ERA in 13 starts since returning from the disabled list Aug. 4. That includes a two-hitter against Atlanta in Game 3 of the division series, and a 12-3 victory over the Marlins in Game 2.

Wood was 3-0 over his last four starts in the regular season, finishing the year with a streak of 17 scoreless innings. In the division series, he held the Braves to three runs and seven hits over two games.

“If we had to pick two guys on the staff to throw, it’d be Prior and Wood,” Karros said. “But that doesn’t guarantee anything.”