Kennedy won his third straight start on Saturday in San Francisco, as he outdueled Tim Lincecum, allowing a run and five hits in seven innings to improve to 18-4, while lowering his earned run average to 2.96.
"If you would have told me that [before the season], I would have been thrilled, with this being the beginning of September," said Kennedy, whose winning percentage is the best in the majors. "When I hear 18 wins, I think of our good bullpen and our timely hitting, really."
Since having a seven-start winning streak halted with a loss to Philadelphia, Kennedy has reeled off three more wins and has pitched to 0.84 ERA in that stretch.
With a win tonight he would become the fourth pitcher in Diamondbacks history with at least 19 wins, joining Randy Johnson (three times), Curt Schilling (twice) and Brandon Webb.
"It doesn't happen when you're on a bad team," Kennedy said.
Kennedy beat the Padres two starts ago and is 4-0 lifetime against them with a 2.19 ERA in six starts.
The Diamondbacks moved closer to a division title on Wednesday when they beat Colorado, 5-3, to take the rubber match of that series at Coors Field and extended their lead over the San Francisco Giants to seven games.
Arizona, whose magic number for clinching the division stands at 13, completed a six-game road trip at 4-2 and has won 13 of its last 15.
"I think we left at six games and we're coming back at seven, so we're making progress," Arizona manager Kirk Gibson said. "None of them are easy. We're getting closer to the initial finish line."
San Diego, meanwhile, dropped two of three to the Giants, but could have a big say in who wins the division, as the Padres are in the midst of a stretch that sees them play 13 straight games against Arizona and San Francisco.
"The bottom line is we've got to keep fighting," San Diego outfielder Cameron Maybin said. "We've got to make these teams beat us -- I still think we can do some special thing."
Getting the call for the Padres tonight will be lefty Cory Luebke, who is 5-8 with a 3.29 ERA. Luebke lost his second straight start on Saturday to Colorado, as he surrendered five runs and eight hits in 4 1/3 innings.
Luebke lost to Kennedy and the D'Backs on August 28 and is 0-2 with a 6.57 ERA in four games (two starts) against them.
Arizona has won seven of its 11 meetings with the Padres this season.