Carter Stewart Jr. struck out eight over seven scoreless innings and Hotaka Yamakawa homered for the third straight game as the Pacific League-leading SoftBank Hawks held on to beat the Rakuten Eagles 5-2 on Sunday. At Fukuoka’s Mizuho PayPay Dome, Stewart (7-2) allowed two walks and two singles. The right-hander left with a 4-0 lead and won his sixth straight decision. “Everything was working great today. The fastball was working great, the split was working great,” said Stewart, who turned pro with SoftBank after being the eighth overall pick in Major League Baseball’s 2018 draft. Yamakawa b…