It’s going fast. Every time Zack Wheeler has taken the mound in his first 10 major-league starts it’s been like a pop quiz of how far he’s come from his last start. Saturday night the rookie righthander made a huge stride. After struggling with command in his first nine starts Wheeler made his first one without giving up a walk.

“It’s already 10 starts?” Wheeler asked with a laugh. “It’s going fast. It definitely is going fast. . . . I am definitely enjoying it trying to learn something new every day and hold my own out there.”

Wheeler held his own into the seventh inning and the bullpen worked out of some tight situations as the Mets beat the Diamondbacks 4-1 at Chase Field.

The Mets (53-61) won for the fourth time in five games and tied the season series with the Diamondbacks (59-56) at 3-3. Lefthander Jon Niese coming back from a partial tear of his rotator cuff makes his first start since June on Sunday in the rubber game.

Wheeler was not the only rookie to have an impact Saturday night. Wilmer Flores drove in three runs including two with a two-out single in the eighth and fellow freshman Juan Lagares went 2-for-4 with a home run.

The Mets’ veteran bullpen flirted with trouble but Scott Rice and Pedro Feliciano got clutch outs and LaTroy Hawkins picked up his third save.

That gave Wheeler (5-2) his fifth win. He went 6.1 innings allowing one run on six hits and striking out four. After being just one of three pitchers in the majors to issue multiple walks in nine straight starts Wheeler did not give up one.