PHOENIX -- Eduardo Rodriguez turned in another dominant outing, striking out nine batters over seven innings, and the Arizona Diamondbacks blanked the Chicago Cubs 2-0 on Wednesday night. The left-hander allowed just two hits, improving to 14-4 on the season and extending his winning streak to four starts.

Rodriguez outpitched Cubs starter Matthew Boyd (8-3), who surrendered three hits and two walks while striking out five over six innings. The only run Boyd allowed came on a solo home run by Jordan Lawlar, who led off the sixth inning by sending a pitch over the fence for his third homer of the year. That was all the offense Arizona needed, though Ryan Waldschmidt added a sacrifice fly in the eighth inning to give the Diamondbacks a two-run cushion.

Rodriguez, who had tossed 5 2/3 scoreless innings against Cincinnati in his previous start, was nearly unhittable against the Cubs. He did not allow a hit until Tyrone Taylor blooped a single to lead off the fifth inning. In the sixth, Pete Crow-Armstrong doubled and advanced to third with one out, but Rodriguez stranded him there after a brief controversy. With two outs, Crow-Armstrong danced down the line as if attempting to steal home, and Rodriguez fired a quick pitch that forced him back. Crow-Armstrong argued vehemently that Rodriguez had balked, and third base coach Quintin Berry had to restrain him as the umpiring crew huddled. After discussion, the crew ruled that no balk occurred, and Rodriguez escaped the inning unscathed.

Boyd was sharp early, erasing walks with inning-ending double plays in the second and third innings. In the fourth, Cubs left fielder Tyrone Taylor threw out Nolan Arenado at second base from deep in the left-field corner, preventing a potential scoring threat. But Lawlar's homer in the sixth was the decisive blow.

Relievers Brandyn Garcia and Juan Morillo finished the two-hitter, with Morillo notching his second save of the season. The Cubs, who currently hold the top National League wild-card spot, have lost five of their last seven games.

Up next, the Cubs will send left-hander David Peterson (7-7, 5.17 ERA) to the mound to open a three-game series against the visiting Cincinnati Reds on Friday. The Diamondbacks have yet to announce a starter for Thursday's series opener at San Francisco, which begins a four-game set.