Aug 4, 2015 3 min read

PITTSBURGH – Jake Arrieta pitched seven strong innings, Anthony Rizzo tied a career high with four hits and the Chicago Cubs beat the Pittsburgh Pirates 5-0 Tuesday night for their sixth straight win.

Arrieta (12-6) allowed two singles – Andrew McCutchen in the fourth and Starling Marte in the seventh – while striking out five and walking three.

Tommy Hunter and Justin Grimm completed the three-hitter with one inning each as the Cubs (58-47) matched their longest winning streak of the season from May 11-16 and moved 11 games over .500 for the first time since the end of the 2008 season.

In his last nine starts, Arrieta is 6-1 with a 1.38 ERA. He improved to 5-1 in his career against the Pirates.

Rizzo doubled and scored in both the third and fifth innings as the first baseman led the Cubs’ 14-hit attack with the fourth four-hit game of his career.

Chris Denorfia had three hits while Starlin Castro doubled home Rizzo twice and Jorge Soler drove in the first and last runs with a bases-loaded walk in the first inning off J.A. Happ (4-7) and a single in the sixth.

Chicago drew within three games of the National League wild card-leading Pirates (61-44), who remained 5 1/2 games behind the St. Louis Cardinals in the NL Central.

Happ had a rocky Pirates’ debut, giving up four runs and eight hits in 4 1/3 innings with two walks and six strikeouts. The lefty was acquired in a trade with Seattle last Friday and was 0-1 with a 9.00 ERA in his last four starts with the Mariners.

Marte had two hits.

The Cubs made it 3-0 in the third when Castro hit his first RBI double and scored on a single by David Ross.

Castro greeted reliever Jared Hughes with his second run-scoring double in the fifth.

Trainer’s room: Cubs: LHP Tsuyoshi Wada (left deltoid inflammation) was activated from the 15-day DL and was optioned to Triple-A Iowa, where he was on a rehab assignment … 3B Kris Bryant was hit on the left hand by a pitch in the sixth inning but stayed in the game.

Pirates: RHP Rob Scahill (right forearm tightness) is scheduled to begin a rehab assignment Thursday by pitching two innings for the rookie-level Gulf Coast League Pirates.

Rotation change: Cubs LHP Jon Lester will be brought back on short rest to start Friday against San Francisco. He threw just 31 pitches during a 1 2/3 innings stint Monday night against the Pirates in a game eventually postponed because of rain.

Up next: Cubs: RHP Dan Haren (7-7, 3.42 ERA) debuts for his new team Wednesday night in the finale of the rain-shortened two-game series after being acquired from the Miami Marlins last Friday in a trade.

Pirates: LHP Jeff Locke (6-6, 4.21) has a 2.81 ERA in his last nine starts and allowed only one home run in 51 1-3 innings during that span.