SEATTLE (AP) — Shota Imanaga allowed one unearned run over 5 1/3 innings, Michael Busch homered in his third straight game and the Chicago Cubs beat the Seattle Mariners 4-1. Seiya Suzuki and Miguel Amaya also hit solo home runs for the Cubs on Saturday. But the focus was on Imanaga continuing the excellent start to his major league career and some timely defense from third baseman Christopher Morel in the sixth to keep the Cubs in front. Imanaga has gone 15 1/3 innings without giving up an earned run. He allowed five hits, struck out four and walked a pair. Seattle starter Emerson Hancock was solid, allowing two runs and four hits over six innings.