With a five-hitter and a two-run double, Willis helped the Florida Marlins beat the Padres 6-0 on Wednesday night.
Willis (16-8) struck out three, walked one and benefited from three double plays. He threw 109 pitches on an 89-degree night.
"He's as good as anybody," San Diego manager Bruce Bochy said. "We aren't the first team he has shut out this year."
Willis leads the major leagues in shutouts and is tied with St. Louis' Chris Carpenter for the most complete games with six. Only Carpenter (17-4) has more wins.
The Marlins' high-kicking left-hander has allowed only two earned runs in 37 innings over his past five starts, an ERA of 0.49.
"The guy has been one of the best pitchers in the league," manager Jack McKeon said. "He loves to compete and loves to play the game. He kept his pitches to a minimum, and as usual he comes up with a key hit that breaks the game open. He's the whole package."
Willis said his double was a bigger thrill than the shutout. He lined a hanging curve over the shortstop's head to put Florida ahead 4-0 in the second inning.
"I'm just swinging," said Willis, who's batting .239. "To be able to get a big hit and put that much pressure on the pitcher is key."
Florida trails NL wild-card leaders Houston and Philadelphia by 1½ games. San Diego fell a game below .500 but remained atop the NL West -- the latest a division leader has had a losing record.
Losing for the first time in five games against Florida this year, the Padres had a tough night all around. Second baseman Mark Loretta fell catching a routine popup in short right field. Miguel Olivo lined out to Willis, then angrily snapped the bat in two over his thigh.
"It was cracked a little bit" by the liner, Olivo said. "I just finished it. It's hard when you're hitting the ball well and the hits don't come."
San Diego did not have a runner reach second base until Damian Jackson doubled with one out in the ninth. Eric Young popped out to end the game.
"I definitely wanted to get that guy," Willis said. "I definitely didn't want to get pulled with two outs."
Williams (6-9) settled down after his rough start and retired the final 10 batters he faced. He pitched five innings and allowed six hits before departing for a pinch hitter.
The Marlins came into the game having scored nine runs in the past five games, and after the early outburst, Padres pitchers retired the final 19 batters.
"Does a 6 1/3-inning no-hitter count?" Williams joked.
Florida scored with two outs in the first when Jeff Conine walked and Delgado homered.
Paul Lo Duca led off the second with a single. Following a forceout, Alex Gonzalez doubled, and Willis' double made it 4-0. Juan Pierre hit an RBI triple and scored on a sacrifice fly by Damion Easley.
"We got some big hits," Delgado said. "That's what we haven't been doing, and I'm as guilty as anybody."
- Florida has won nine of the last 11 games against the Padres at home.
- Because of injuries, the Marlins have put their eight opening-day regulars on the field together only once since July 22.
- Pierre is 12-for-25 (.480) lifetime against Williams.
- The victory was the shortest nine-inning game for Florida since Sept. 25, 2004.