Yu Darvish struck out seven batters over six scoreless innings, and the Chicago Cubs cruised to a 6-3 win over the visiting Pittsburgh Pirates on Friday night to open a three-game series.Darvish (1-1) limited the Pirates to two hits while issuing only one walk. The right-hander threw 56 of 86 pitches for strikes as the Cubs won for the fifth time in seven games to start the regular season.Jason Kipnis homered for Chicago, while Jason Heyward finished 2-for-4 with two RBIs. Anthony Rizzo also had two RBIs.Pirates right-hander Trevor Williams (0-2) drew the loss after giving up three runs (two earned) on four hits in 4 2/3 innings. Williams walked three and struck out six.The Cubs opened the scoring in the third inning. Kris Bryant drew a one-out walk, advanced to second base when Rizzo was hit by a pitch, and scored on Williams’ throwing error as he tried to throw out Javier Baez on a bunt.In the fifth, Chicago extended its lead to 4-0. Heyward faced two strikes with two outs when he knocked a two-run single to right field, scoring Bryant from third base and Kyle Schwarber from second.The Pirates got on the board in the eighth inning when Jarrod Dyson drove a ground-ball single into right field to bring home Gregory Polanco from second base. It was the third RBI in six games for Dyson.Rizzo gave the Cubs a comfortable 6-1 lead with a two-run single in the bottom of the eighth. His hit to left-center field drove in Ian Happ and Nico Hoerner.The Pirates capped the scoring on back-to-back homers by Josh Bell and Colin Moran in the ninth. Both blasts came against reliever Craig Kimbrel, who has given up 11 homers in 22 innings since joining the Cubs last season.The Cubs improved to 3-1 at home. The Pirates dropped to 1-3 on the road.