For a supposed No. 5 starter, Pat Corbin sure is turning into one heck of an ace. The Diamondbacks left-hander continued his torrid start to the season Thursday night at Chase Field against the Philadelphia Phillies. And he made a little history along the way. In allowing just one earned run over 6 1/3 innings during Arizona’s 2-1 victory, Corbin became the first Diamondbacks pitcher in club history to pitch at least six innings and allow two or fewer runs in each of his first seven starts. Only he and Dan Haren, the key component in the trade with the Angels that brought Corbin here, had done it in six consecutive starts to begin a season. Haren did it for the Diamondbacks in 2009. The last pitcher in the majors to do it at least seven times was Ubaldo Jimenez, who did it in 12 consecutive games for the Rockies in 2010. Corbin improved to 5-0 and lowered his ERA to 1.75 against a pretty talented Phillies lineup featuring Jimmy Rollins, Chase Utley, Michael Young and Ryan Howard. “It’s exciting, but I want to keep myself level-headed and make sure I don’t get too big on myself,” Corbin said. “I just want to go out there and improve every start.” He didn’t get into any trouble until the seventh inning, when he allowed two singles, and manager Kirk Gibson decided to remove him for reliever Matt Reynolds. Kevin Frandsen’s fielder’s choice scored a run that was charged to Corbin, but that was the extent of the damage. “I felt fine,” said Corbin, who threw 89 pitches. “It was Gibby’s decision, but (Reynolds) got out of it with the lead, and that’s what you ask for in that situation.” The Diamondbacks are 7-0 in Corbin’s starts.