Someone needs to talk to Merrill Kelly because his ERA is reaching stratoospheric levels.

Kelly worked 4 1/3 innings on Sunday, giving up eight hits and six earned runs as the Chicago Cubs clinched a series sweep by downing the Diamondbacks 8-4. Kelly was bit by the walks bug, giving the Cubs three walks while he also struck out five.

But Kelly is now 1-3 this season and the Diamondbacks' staff might need to sit with Kelly and go over some pitching strategy.

Three Diamondbacks relievers followed Kelly on Sunday afternoon. Brandon Pfaadt worked 2 1/3 innings in there, giving up four hits and two runs (both earned), walked three, and struck out one.

Arizona's Ildemaro Vargas went 1-for-4 in the loss, maybe starting yet another hit streak one day after his 27-game hitting streak came to an end.

Cubs starter Matthew Boyd picked up the win, going to 2-1 this season. Boyd worked six innings, giving up four hits, two runs (both earned), walked one, and struck out five. Three Cubs relievers followed Boyd to the mound at Wrigley Field in Chicago, shutting down the Diamondbacks' offense.

In the top of the second inning, Arizona's Gabriel Moreno hit a two-run home run, bringing Nolan Arenado ahead of him. The Diamondbacks went up 2-0 at that point.

But the Cubs scored a run in their half of the second, and added two more in the third inning. Moisés Ballesteros hit a two-run homer, his sixth homer this season, and brought home Nico Hoerner to give Chicago a 3-2 lead.

With one out in the bottom of the fifth, the Cubs loaded the bases. Michael Busch cleared the bases with his first triple this season, scoring Ballesteros, Alex Bregman, and Ian Happ. The Cubs took a commanding 6-2 lead.

Coming out of the seventh-inning stretch, Chicago added two more runs and extended its lead over Arizona to 8-2. 

In the top of the ninth, Adrian Del Castillo hit his third home run this season, a two-run blast. Lourdes Gurriel Jr. scored ahead of Del Castillo, but the Diamondbacks couldn't add anymore runs and took the loss.

The Diamondbacks went 2-for-5 with runners in scoring position and ended up leaving five runners on base. The Cubs were 4-for-13 with runners in scoring position and left 10 runners on base against Arizona.

Gurriel went 2-for-3 against Chicago pitching and he was the only Diamondbacks player to have more than one hit on Sunday afternoon.

Arizona is now 16-17 this season, sitting in third place in the National League West Division. As for the Cubs, they extend their stranglehold on the National League Central Division lead with a 22-12 mark.

The Diamondbacks get a day off on Monday, then start a homestand on Tuesday night that will see the Pittsburgh Pirates and New York Mets visit the Valley of the Sun and Chase Field in Downtown Phoenix. The D-backs and Pirates open their series on Tuesday night.

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