CHICAGO -- — Cade Horton threw four-hit ball into the seventh inning, Ian Happ broke the game open with a three-run homer in the sixth inning and the Chicago Cubs routed the Washington Nationals 10-2 on Saturday. Miguel Amaya homered and finished with two hits and two RBI, and Pete Crow-Armstrong added two hits. Nico Hoerner, Matt Shaw and Carson Kelly drove in runs as the Cubs avenged Thursday's 10-4 opening day loss. Horton (1-0), the runner-up in the 2025 NL Rookie of the Year race, retired the first nine batters he faced before James Wood led off the fourth with a solo homer. The 24-year-old right-hander was charged with two runs in 6 1/3 innings, with four strikeouts and a walk. Three Chicago relievers followed Horton and didn't allow a hit. Washington shortstop CJ Abrams missed the game due to a death in the family. Replacement Nasim Nuñez singled in a run. Miles Mikolas (0-1) allowed six runs, four earned, on seven hits in five innings in his first start for the Nationals after signing as a free agent. Horton pitched only three innings in his previous regular-season start, on Sept. 23 against the New York Mets, before leaving with back tightness that was diagnosed as a cracked right rib. He missed the Cubs' playoff series against San Diego and Milwaukee, finishing last season at 11-4 with a 2.67 ERA. The Cubs grabbed a 4-0 lead in the second. Shaw’s sacrifice fly opened the scoring, then Amaya's bloop single scored a second run. Two unearned runs scored on Michael Busch’s pop after Daylen Lile collided with Nuñez in short left field. Wood’s drive cut it to 4-1 in the fourth, but Amaya replied with a solo drive in the bottom half. The teams exchanged runs again in the fifth. Happ greeted Ken Waldichuk, Washington's second reliever, with a shot to left, making it 9-2. Up next Washington RHP Jake Irvin faces Chicago LHP Shota Imanaga in Sunday’s series finale. ------ AP MLB: https://apnews.com/hub/mlb