CHICAGO -- Mark Cuban picked a good night to have a front-row seat at Wrigley Field. Not only did his favorite baseball team break out of a slump, it unleashed its most convincing beating in years.

The longtime Cubs fan and prospective owner watched Geovany Soto hit two three-run homers as Chicago pounded the Milwaukee Brewers 19-5 on Wednesday night.

The Cubs' biggest outburst since a 20-1 whipping of the Los Angeles Dodgers on May 5, 2001, gave them a club-record 17 victories in April. The Brewers had not allowed that many runs since they gave up 19 at Colorado on Aug. 8.

The Cubs scored six runs each in the first and eighth innings and leading the charge was a rookie who appeared in only 18 games last season.

Soto connected in the first to cap the outburst and finished off a five-run fourth by going deep again off reliever Brian Shouse, who had just come in for Jeff Suppan (1-1). It was the first multihomer game for Soto, who made a big impression by batting .389 for the Cubs last year. The six RBI is a career high.

"Guys have really helped me with the mental aspect of the game," he said. "You have to go through the bad times to learn. Hopefully, it'll never happen again."

The rout had to please Cuban, who finished off a busy day by watching his favorite baseball team from the Tribune Company's seats next to the Cubs' dugout. The Dallas Mavericks owner fired coach Avery Johnson by cell phone from Chicago. Then had a front-row seat and a beverage in hand at Wrigley Field.

Cuban's interest in buying the Cubs from Tribune is no secret, but he apparently wasn't in the mood to talk to most members of the media -- ESPN's Erin Andrews being the exception. Others had been shooed away by an usher.

A longtime fan and occasional visitor to Wrigley Field over the years, he had to like what he saw before he left in the middle of the fifth with the Cubs leading 12-3.

After losing four of five and falling 10-7 in the opener of this three-game set, the NL Central leaders wasted no time jumping on Suppan.

Soto, who struck out in eight consecutive at-bats before going 2-for-4 on Tuesday, capped the first-inning outburst by lining a pitch out to left.

"It shows the kind of player he is," Ryan Dempster said. "He's gone through some adversity."

The rout was well under way before Soto stepped to the plate.

Back-to-back RBI doubles off the wall by Derrek Lee and Aramis Ramirez made it 3-0 with no outs, and the Cubs continued to pound away at Suppan.

The veteran right-hander allowed a career-high 11 runs (eight earned) and 11 hits over 3 2/3 innings and his ERA jumped from 3.48 to 5.19.

"They were on the attack, and I kept missing down the middle," he said. "It's my job to keep us in the game, and I didn't do that from the get-go."

An RBI single by Mark DeRosa finally knocked him out and Soto greeted Shouse by hitting his fifth home run this year.

He got a loud ovation when he came to bat with runners on first and second in the sixth, but struck out swinging.

"I did have one two-homer game in Double-A, but I didn't have six RBIs," Soto said.

The six RBI gave him 20 for the month. Along with Lee and Ramirez at 23 and 22, respectively, the Cubs have two or more players with 20 RBI in April for the first time.

"That's why you've got to stay in the game, stay focused," Ramirez said about Soto's performance. "You never know what's going to happen tomorrow."

The Cubs' 17 hits were one shy of their season high.

The onslaught made things easy for Dempster (4-0) and probably whetted Alfonso Soriano's appetite to return. He'll be back at the top of the order and in left field on Thursday after spending 15 days on the disabled list because of a strained right calf.

Dempster allowed three runs and four hits in six innings but walked five while striking out one.

Milwaukee's Rickie Weeks and Ryan Braun had two hits apiece, and Mike Rivera hit his first home run of the season -- a two-run shot off Bob Howry in the seventh. As bad as Suppan was, Derrick Turnbow absorbed a six-run eighth.

"It really was just the way the night went," manager Ned Yost said.

Notes

• Chicago's Kosuke Fukudome got an infield double leading off the third when his shot caromed off Suppan's foot and past first baseman Prince Fielder into foul territory.
• Yost said Ben Sheets, who had skipped a start because of a sore triceps, felt fine after pitching on Tuesday.