By David Craven Manager Russell Martin hailed the guy he calls “boss” as Southampton surged into the top-two. Saints stretched their unbeaten run to 23 games with goals from Jan Bednarek, on his 200th club appearance, and top scorer Adam Armstrong. Poland centre-half Bednarek headed home after just four minutes and gave a masterclass as his side eased past rock-bottom Rotherham. Stuart Armstrong also celebrated his double-ton for the visitors. Martin said: “They’ve both been massive for us. Huge. But Janny is for the courage he shows with ball. He’s been one of the best players in the league. …