Despite battling a respiratory ailment, Arizona's Webb gave up one hit and struck out two in two shutuout innings and the Chicago White Sox defeated the Diamondbacks 7-5 on Friday afternoon.
"His offspeed stuff seems to just get better and better," Arizona manager Bob Melvin said.
Buehrle also threw two scoreless innings, allowing a hit and a walk and striking out two.
Pitching on an 82-degree afternoon in the desert, Webb retired the side in order in the first, striking out Orlando Cabrera. In the second, Webb gave up a leadoff single to Jermaine Dye, who was doubled off first on A.J. Pierzynski's liner to second baseman Orlando Hudson.
Webb capped his 16-pitch outing by striking out Josh Fields. Webb left Tucson Electric Park immediately after his outing and didn't speak to reporters.
Melvin said Webb wanted to pitch despite his illness.
"It was kind of his call, but he wants to stay on schedule," Melvin said. "There was no telling if he was going to be any better tomorrow."
The Diamondbacks are counting on the 28-year-old Webb as they bid for their fifth NL West title in 11 seasons. Webb helped lead the Diamondbacks to the NL West crown last season, turning in an even stronger performance than he had in 2006, when he won the NL Cy Young Award.
Webb won a career-high 18 games in 2007, two more than the previous year, and shaved .09 points off his ERA, finishing at 3.01. He also pitched 236 1-3 innings with 194 strikeouts, both career highs.
Buehrle, who threw a no-hitter last April, showed no sign of the shoulder tightness that kept him out of an intrasquad game on Monday.
"It felt real good, probably the best I've felt in a while," he said.
Buehrle said he could have pitched another inning, but the White Sox don't want to push him. Buehrle has thrown 1,577 innings since 2001, and the club wants to protect its investment after giving him a $56-million, four-year contract extension last year.
Buehrle worked a 1-2-3 second inning, striking out Justin Upton.