The Pittsburgh Pirates had one of the majors' most effective rotations heading to Arizona.
That hasn't changed in two games against a Diamondbacks lineup that's laboring.
Francisco Liriano will try to help the Pirates to a fifth consecutive win and first three-game sweep in Arizona on Sunday.
Pittsburgh's starters had a 3.03 ERA before this series and has lowered it to 2.79 by allowing one run in a pair of wins. The Pirates (10-8) claimed a 2-1 victory Saturday with Starling Marte's RBI single in the ninth.
They've won four in a row in April for the first time in 2008. Their last five-game win streak in that month was in 2007.
"It's another thing we had on our to-do list coming in," manager Clint Hurdle said. "We're working hard to get better every single day collectively as a club."
The next item on Liriano's to-do list is procure his first win. The left-hander has received a combined four runs of support in three starts.
The left-hander (0-1, 3.00 ERA) left Tuesday's start against the Chicago Cubs with the Pirates trailing by a run. He gave up three runs and three hits in five innings in a 9-8 loss while striking out nine.
Liriano will next face an Arizona lineup that's batting .218 in its last six games and has scored one run in four of those contests. The Diamondbacks (8-9) hit .261 and plated 54 runs in their first 11 games.
Paul Goldschmidt is 2 for 13 with seven men left on base in his last four games, but three of his four hits against lefties on the season have been homers.
The Pirates will try to keep Arizona at bay again while recording their first sweep in the series since September 2010. Their only sweep at Chase Field was in two games in August 1998, the Diamondbacks' first season.
Jeremy Hellickson will try to prevent that by extending a streak of solid efforts by Arizona's starters. The Diamondbacks rotation has given up three earned runs or fewer while pitching at least six innings in nine consecutive games, its longest streak since an 11-game run in September 2008.
"It's contagious," Hellickson said. "If a guy throw six, seven innings and does well, you don't want to be that guy who goes out and throw four or five."
Hellickson (1-2, 4.58) snapped an 11-start winless streak and earned his first win with Arizona last Sunday, yielding one run in 6 2-3 innings in a 5-1 victory in San Francisco. The righty, who will be facing the Pirates for the first time, had a 6.55 ERA in losing his first two outings for the Diamondbacks.
Liriano has a 3.00 ERA without a decision in two career starts against Arizona, both at Chase Field. He gave up two runs in six innings in his only meeting in 2014, a 3-2 loss in 10 innings Aug. 3.
Marte, batting .357 with 11 RBIs in his last nine contests, has hit safely in all 15 career games against Arizona, going 22 for 63 (.349) with 10 extra-base hits and 12 RBIs.