PHOENIX -- The key moment on Sunday, Cubs pitcher Jacob Arrieta said, was in the fifth inning. Rookie catcher Victor Caratini had given Arrieta a heads-up before it began, even though the right-hander was facing the D-backs' 7-8-9 hitters. It didn't help that Arrieta walked both Ketel Marte and Gregor Blanco to start the inning.
"I got a little out of whack there, but was able to adjust and have a nice sixth inning and get a big double play ball," Arrieta said. "For me, at that point, with a one-run lead, that was the turning point of the game."
The D-backs did score in the fifth on a sacrifice fly by David Peralta but it wasn't enough as the Cubs won, 7-2, to win the series and finish their last West Coast road trip at 3-3. The win, coupled with the Cardinals' loss on Sunday, moved the Cubs back into a one-game lead in the National League Central.

Chicago is 18-10 since the All-Star break, the second-best record in the Majors behind the Dodgers. Arrieta has been a big part of that surge. He's 4-1 with a 2.09 ERA since the break. What's the difference?
"Fastball command," Cubs manager Joe Maddon said. "His velocity is ticking up, command is back, slider is back. The stuff is more familiar right now."
He held the D-backs to three hits -- all by Jake Lamb -- over six innings and was lifted after 91 pitches.
"I thought we had a pretty good approach," Arizona manager Torey Lovullo said. "I think Arrieta had good stuff and sometimes you have to tip your cap to him. His fastball was down and aggressive, I think it was in the low- to mid-90s, and he had a quality breaking ball."
Arrieta was 8-7 with a 4.35 ERA in the first half. What's changed?
"Mechanically, I've been pretty good and staying back, giving myself time and allowing myself to get on top of the baseball and drive it down through the strike zone," Arrieta said. "If I do that, it creates difficulty for the hitter with sink and being able to establish multiple breaking balls."
He zipped through the first three innings, needing 40 pitches. That's what he's aiming for.
"I want to come out and establish good sink early in the ballgame and try to force early contact and try to get the third or fourth inning at 40 pitches," he said. "If I'm able to get through the first [inning], the first time through the order with that established, my job becomes easier. I know as the game progresses, if I have the feel of that pitch, at least one breaking ball, I'll be in good shape."
Cubs starting pitchers are 15-5 since the All-Star break, including 17 quality starts. That kind of consistency will get a team to the postseason. Arrieta said they're not looking ahead.
"We can't assume we're in October," he said. "We still have to get there. I still have my best pitching ahead of me. I think a lot of guys in this room are in the same boat. We've picked it up lately and we're playing pretty good baseball. If we keep that up, we'll be in good shape."