Willis became the major leagues' first six-game winner, allowing five hits in seven innings to help the Florida Marlins beat Colorado 7-0 on Friday.
"Every time he goes on the mound, we feel like he's going to win," Marlins slugger Miguel Cabrera said. "I want him to pitch every day."
The Rockies have baseball's worst record at 6-20, and their nine-game losing streak matches the third-longest in franchise history. They're 1-14 on the road.
"These are definitely hard times," said five-time All-Star Todd Helton, who struck out all three times he faced Willis. "All we can do is come to the yard, battle our butts off and see what happens."
Adding to Colorado's woes, left-hander Joe Kennedy (1-4) limped out of the game trailing 1-0 after a sharp one-hop grounder deflected off his left leg below the ankle in the sixth inning. X-rays were negative, but Kennedy said he might miss his next start.
Florida scored three more times in the inning, and that was plenty for Willis, who tied a career high with 10 strikeouts. The left-hander has won every start this season, and his ERA of 1.07 is the lowest in the majors.
"I felt strong," Willis said. "I was able to stay down in the zone. That's my key, because I don't throw 100 mph. I can't live up in the zone. In all my starts I've been trying to stay down, and hopefully they swing at it."
Willis threw 110 pitches, 80 for strikes. He walked two, matching his season high, and improved to 4-0 at home with an 0.58 ERA.
"He has been outstanding," manager Jack McKeon said. "He has so much confidence right now."
"He's off to a great start," Rockies manager Clint Hurdle said. "He has fun out there, and they respond to him."
The game, the Marlins' first since their latest bid for a new ballpark was rejected by the Florida Legislature, drew a crowd of 21,566.
Florida took the lead in the second. Cabrera walked, advanced on a groundout and an infield single and then came home on Mike Lowell's
sacrifice fly, beating the throw with a nifty slide.
Cabrera led off the sixth with a single, and Juan Encarnacion drilled a single off Kennedy.
"It was my instinct," Kennedy said. "I put my foot down for the kick save."
He scrambled to retrieve the ball and threw as he was falling backward. The errant heave sailed over first baseman Helton's head, and runners advanced to second and third as Kennedy remained on his back in pain.
After being checked by a trainer, Kennedy rose and was helped off the field. He was charged with three runs in five-plus innings and has lost all five career starts against Florida.
"They're an elite team," Hurdle said. "They've got horses in the starting rotation."
With Willis' performance, Florida starters lowered their ERA to 2.55, best in the majors.
Lowell made a bad throw for his first error of the season. ... Willis last faced Colorado in his major-league debut in May 2003 in Miami. He pitched six innings and wasn't involved in the decision. ... Kennedy is 0-4 on the road with an ERA of 8.31. ... Byung-Hyun Kim let in a run in the seventh when he threw a wild pitch. He has five in 13 innings. ... Chasing a foul ball that fell untouched, right fielder Mohr ran into a security guard. Neither was hurt.
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