CHICAGO -- Miguel Montero was not about to party after a loss.
As Montero's solo blast to left off Brewers reliever Blaine Boyer settled into the left field bleachers the celebrations exploded around him.
"I don't think it's a good feeling when you lose and you celebrate," said Montero, who clubbed his third career walk-off home run. "It worked out pretty good didn't it?"
Montero's dramatics capped a day that began with a division title clinching just after midnight and concluded with a clubhouse party for the newly-minted National League Central champs (94-53).
The celebration shifted inside as jubilant players doused themselves with Champagne and beer, exchanged fist bumps and hugs and marveled at how they put together the Major League's best record.
But the NL Central title is just the first step.
"I don't think I've been on a team this talented and capable of dominating at times," said second baseman Ben Zobrist. "It's such a different animal when you get to the post-season. Everybody's good and you've really got to play well at the right time.
"But we're in a good spot right now."
Cubs reliever Aroldis Chapman (1-1) struck out the side in the 10th for the victory while Boyer (2-4) took the loss after facing just one batter.
Chicago scored twice in the ninth off Milwaukee reliever Carlos Torres to force a 4-4 tie and extra innings.
Tommy La Stella reached on a grounder that was bobbled by first baseman Chris Carter, leaving runners on first and second, before Torres hit second baseman Munenori Kawasaki with a pitch to load the bases.
Pinch hitter Addison Russell forced the 4-4 tie by beating out an infield hit that scored Coghlan.
Scooter Gennett had given Milwaukee a 4-2 lead with a go-ahead, two-run homer in the seventh.
The Brewers (66-82) saw a two-game winning streak snapped.
They also had bad news with a season-ending injury to center fielder Keon Broxton, who suffered an apparent broken wrist after running into Wrigley Field's brick outfield wall while chasing La Stella's fly ball in the third inning.
"It's very disappointing," Broxton said. "As soon as I hit, I knew my wrist was broken. I've had broken bones before, so I know what it feels like. While I was on the ground I tried to move it around to see if I could move it and it wasn't budging too much."
The Cubs returned to action with a significantly altered lineup as manager Joe Maddon rested his regular position players.
The most experienced Cub was right-handed starter John Lackey, who had no decision after pitching seven innings, his longest outing since returning from the disabled list earlier this month.
Brewers starter Chase Anderson also had no decision. He worked six innings, allowed two runs on five hits while striking out three and walked three.
"The guys they had in there today, that's still a really good team," Anderson said. "Those guys have so much depth, that's been how they won so well this year."
Lackey gave up four earned runs on nine hits -- including three home runs. He walked two and struck out eight
Milwaukee grabbed a 1-0 lead in the second inning on Orlando Arcia first pitch home run deep into the left field bleachers for a 1-0 lead. Ryan Braun's team-leading 28th homer of the season made it 2-0 lead in the third.
Albert Almora's two-run homer in the fifth forced a 2-2 tie while Gennett clubbed his 13th home run of the season in the seventh -- delivering his second go-ahead run in two games -- to give Milwaukee a 4-2 lead.
Chicago missed a chance to clinch outright with a 5-4 loss to the Brewers on Thursday, but the San Francisco Giants' 6-2 win over St. Louis as midnight approached knocked the Cardinals out of contention and gave the Cubs the crown.
NOTES: Brewers RHP Michael Blazek threw a simulated game on Thursday and will try another next week at home. The Milwaukee reliever could be cleared to pitch for the season's final stretch. ... Milwaukee sends RHP Zach Davies (10-7, 3.87 ERA) against Cubs RHP Jake Arrieta (17-6, 2.91) in Saturday's third game of the series. ... The NL Central champion Cubs have reached the postseason in back-to-back seasons, only the fourth time in franchise history and first since 2007-08. ... LHP Jon Lester's current run of pitching at least six innings and allowing two or fewer runs over his last nine starts matches the longest single-season streak by a Cub, joining Jake Arrieta (2015) and Bill Lee (1938). ... With 31 homers and 101 RBIs entering Friday, 3B Anthony Rizzo is the second left-hander in Cubs history with at least 30 homers and 100 RBIs in a season.