Parker, MLB.com's No. 29 prospect, enjoyed his best outing of the season Friday as the Mobile BayBears beat the Birmingham Barons, 8-1.
The 22-year-old right-hander (2-2) allowed one run on five hits over five innings. He threw 88 pitches and struck out six while walking three and hitting a batter.
While they may not be the numbers D-backs fans expected when speculating about Parker's big league arrival date, he's been better in consecutive starts after a difficult start to his third Minor League season.
The ninth player taken in the 2007 Draft, he performed above the hopes of Arizona's brass before undergoing Tommy John surgery and missing the 2010 season. In his first two outings this year, he surrendered 15 runs -- 14 earned -- on 13 hits and six walks over seven innings.
On Friday, he spotted the Barons a run in the first when Brandon Short took him deep on a 2-0 pitch. But Parker (2-2) worked in and out of trouble in each of his final four innings and lowered his ERA from 12.00 to 9.00.
The win was his first since June 24, 2009, when he gave up a run on three hits over five innings against West Tenn.
Six different BayBears plated runs, including Ryan Wheeler, who went 2-for-4 with a pair of RBIs.