CHICAGO (AP) The Colorado Rockies arrived at Wrigley Field this week with a chance to solidify their standing as a National League contender, and they haven't missed a beat.

Of course, these Chicago Cubs look a long way from their World Series-winning form.

Mark Reynolds and Charlie Blackmon homered, rookie Jeff Hoffman pitched neatly into the seventh inning and the Rockies won their seventh straight game, beating the Cubs 9-1 Saturday. Colorado can complete a four-game sweep of the reigning champs Sunday behind breakout rookie right-hander Antonio Senzatela.

''These guys are growing before our eyes, and it's great stuff and good to see,'' manager Bud Black said. ''Charlie's having a big series. Mark had a big day today. A lot of contributors today.''

The Rockies have their longest winning streak since 2011, when they started a run of six straight losing seasons. The Cubs lost their fourth in a row, dropping them to 30-31.

Reynolds had his fourth career four-hit game, including his 17th homer, and Nolan Arenado had a three-run double during a five-run ninth inning. The Rockies, who have the best record in the NL, improved to 24-10 on the road.

One of four rookies in the Rockies' rotation, the 24-year-old Hoffman (4-0) allowed one run and struck out eight in 6 1/3 innings. Four Colorado relievers kept Chicago scoreless the rest of the way.

''It was awesome,'' Hoffman said of his first start at Wrigley Field. ''Facing a great lineup and to be able to go out there and do what I did and execute - and the team to play the way it did - was special.''

Cubs starter Eddie Butler (3-2) pitched five innings and gave up three runs and six hits in his first outing against his former team. Willson Contreras drove in the only run for Chicago, now sliding after a five-game winning streak.

''We just have to do a better job at the plate,'' manager Joe Maddon said. ''I don't have any strong explanation for it, but a lot of guys are struggling badly at the same time.''

Reigning MVP Kris Bryant joined the Cubs in 2015 and isn't used to losing.

''This is probably, I guess, the lowest point that I've been at here,'' Bryant said. ''But it's really not bad when you look at in context of the division.''

Chicago entered the day two games behind Milwaukee in the NL Central.

Hoffman dominated in his fourth start and third straight solid outing. The right-hander was one of four players the Rockies acquired from Toronto in a July 2015 trade that sent All-Star shortstop Troy Tulowitzki to the Blue Jays.

Anthony Rizzo, the third Chicago batter in the first, blooped a single to left, then Hoffman didn't permit another hit until Jason Heyward's lined single with one out in the seventh. Albert Almora Jr. and Contreras then followed with singles for the Cubs' only run.

''We didn't hit any balls hard basically until that inning when we did string together some singles,'' Maddon said.

The Rockies took a 2-0 lead in the first when DJ LeMahieu and Reynolds each doubled home a run.

Reynolds homered over the left field stands onto Waveland Avenue, making it 3-0 in the fourth. Blackmon hit his 15th homer over the right field bleachers in the seventh.

RUSSELL RETURNS

Addison Russell returned to Cubs lineup, two days after Major League Baseball began an investigation of the All-Star shortstop in the wake of domestic violence allegations in a deleted social media post. The Cubs told Russell not to come to the ballpark Thursday for a game against the Rockies, but he rejoined the team on Friday and didn't play. Russell, who entered the game hitting .209, went 0 for 2 before being lifted for a pinch hitter in the seventh.

QUICK TRIP

The Cubs recalled RHP Felix Pena from Triple-A Iowa and optioned righty Seth Frankoff to the farm club. Frankoff made his major league debut on Friday - and took the loss against the Rockies - after being recalled to fill a roster spot for righty Kyle Hendricks, who's on the DL (right had tendinitis).

UP NEXT

Senzatela (8-2, 3.56) will make his first career start at Wrigley Field and try to become the NL's first nine-game winner on Sunday afternoon in the finale of the four-game series. The Cubs will counter with RHP Jake Arrieta (6-4, 4.46).

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