San Francisco fell to 1-4 and will look to avoid a three-game sweep today.
Lowe (1-1) was efficient in seven strong innings. He allowed four hits and one run. Takashi Saito pitched the ninth for his third save in as many games.
Giants starter Russ Ortiz (0-1) lost his 12th straight decision and failed to earn his first win since Aug. 29, 2005. Ortiz allowed three runs and seven hits in five innings.
CINCINNATI - Adam Dunn's wind-blown fly ball deflected off Xavier Nady's glove and cleared the wall for a two-run homer, a goofy play that set the tone for the Reds' win.
Dunn's third homer off Tony Armas (0-1) helped the Reds improve to 4-1 on a bitterly cold afternoon. Edwin Encarnacion had three hits, including a bases-loaded single that put Cincinnati ahead to stay.
Blowing into his cupped right hand between pitches, Aaron Harang (2-0) persevered for 5 2-3 innings to get the victory. David Weathers pitched the ninth for his second save in as many chances.
MILWAUKEE - Carlos Zambrano allowed three runs in seven innings and hit an RBI single to lead the Cubs to the win.
Zambrano (1-1) struck out four of the first six batters he faced and cruised through three perfect innings to start the game before allowing a solo home run to Rickie Weeks to lead off the fourth.
Ryan Dempster pitched the ninth for his second save.
HOUSTON - Roy Oswalt pitched a five-hitter and Carlos Lee and Lance Berkman homered to lift the Astros to their first victory of the season.
Oswalt (1-0) struck out four and allowed one run to earn his 99th career win.
Lee hit his first home run in the sixth inning.
Cardinals right-hander Anthony Reyes (0-1) allowed five hits and three runs in five innings in his 2007 debut.
WASHINGTON - Brandon Webb struck out eight in seven sharp innings for the Diamondbacks. Webb (1-0), last year's NL Cy Young Award winner, allowed one run and seven hits.
Eric Byrnes homered for the Diamondbacks.
John Patterson (0-2) yielded three runs and four hits in five innings, and Austin Kearns homered for the Washington.
MIAMI - Dontrelle Willis pitched six innings for his second victory in as many starts, and Josh Willingham drove in four runs for Florida.
Willingham had hits in his first three at-bats and batted in the seventh needing a single to become the first player to hit for the cycle in the Marlins' 15-year history. He fouled off five two-strike pitches from Ryan Madson, then struck out swinging.
Willis (2-0) allowed three runs - all on Jimmy Rollins' inside-the-park homer - and struck out nine.