CHICAGO -- Jake Arrieta struck out five and allowed four hits in seven innings in his first appearance against his former team as the Chicago Cubs beat the Baltimore Orioles 4-1 on Friday afternoon.

Arrieta, acquired in a trade with Baltimore in July 2013, allowed a seventh-inning home run to major league leader Nelson Cruz and improved to 7-4 for only his second win since late June. Hector Rondon worked a perfect ninth inning for his 20th save.

Luis Valbuena went 2-for-4 with an RBI and scored a run for the Cubs. Rookie Javier Baez collected his sixth home run in his first 18 games.

Chicago broke a scoreless tie in the fourth inning with Valbuena's 12th home run of the year, a solo shot to right-center field for a 1-0 lead. Then with two outs, Ryan Sweeney doubled to left and came home on Logan Watkins' base hit to make it 2-0.