Chicago manager Dusty Baker said the handshakes exchanged on the field after the victory were something to savor.
"When you're winning and you go out there after the game, it feels like Little League stuff," Baker said. "And when you don't do it for a long time, it feels like the World Series. It was a big win for us."
Willis (13-4) was bidding to become baseball's first 14-game winner. Instead, he struggled through his shortest outing this season, allowing a career-high eight runs, all earned, in 4 1/3 innings. His ERA rose from 1.89 to 2.39.
"My location wasn't there," Willis said. "I was just missing, and they took advantage."
Carlos Zambrano (6-4) gave up six hits and six walks but allowed only three runs in seven innings.
"My sinker was moving a lot, more than normal," he said. "I was a little uncomfortable, but fortunately we won the game and got out of the streak."
Ryan Dempster gave up a single and hit a batter in the ninth before earning his 13th save in 14 chances.
Burnitz helped Chicago build an 8-1 lead with a two-run homer in the third aided by a 20-mph wind -- the fringe effects of Hurricane Dennis.
"Today I thought every ball in the air had a chance," Willis said.
Rain delayed the game for 57 minutes in the top of the ninth, and the wind changed the course of several fly balls. It also blew Zambrano's cap from the mound to the first-base line.
Burnitz doubled home a run in the fifth. Jerry Hairston had two RBI singles for Chicago.
Murton, recalled late Thursday from Double-A Tennessee, singled in his first at-bat. He also walked and scored, hit a sacrifice fly and doubled.
A Fort Lauderdale native, Murton said he attended his first major-league game in the mid-1990s in Miami.
"Obviously, my first time playing in the big leagues in the same park was pretty cool," he said.
The Cubs' highest-scoring performance since June 14 -- also against Florida -- came without All-Star first baseman Derrek Lee. Nursing a sore left shoulder, he sat out his third consecutive game but said he expects to play Saturday.
Miguel Cabrera hit a solo homer, his 17th, for Florida.
After Michael Barrett singled in the third, the wind pushed Burnitz's high fly barely over the wall. An RBI single by Hairston and Walker's run-scoring double made it 5-1 in the fourth.
After Florida closed the margin to 8-6, Neifi Perez hit a sacrifice fly in the ninth.
Willis hit a ball off his right foot batting in the third inning, hopped away from the batter's box and knelt in pain. But he stayed in the game and threw another 39 pitches before departing.
"Once I got back on the mound, it was OK," he said.
- Florida RF Juan Encarnacion bruised his left forearm when hit by a pitch in the ninth inning, and he may sit out Saturday's game. X-rays were negative.
- Marlins reliever Randy Messenger bunted for a single in his first major-league at-bat.
- The Cubs' run in the ninth off Todd Jones ended a streak of 16 consecutive scoreless innings by Florida's bullpen.
- Juan Pierre went 0-for-3 against Zambrano, dropping his lifetime average against the right-hander to .133 (2-for-15).