Bayern Munich scored three times in the first 21 minutes and Leroy Sane got a brace as the Germans maintained their perfect Champions League record with a 5-0 demolition of Viktoria Plzen on Tuesday. Germany winger Sane smashed the opener high into the net in the seventh minute, Serge Gnabry got the second in the 13th into the bottom right corner, and Sadio Mane the third in the 21st with a low shot after getting past several defenders. Bayern continued to attack and in-form Sane got his second in the 50th, set up superbly by Mane’s high defence-splitting pass. Nine minutes later substitute Er…