The Altona Bisons and Pembina Valley Orioles opened their respective Manitoba Junior Baseball League second round series on Sunday. Colin Walder singled home Brendan Wiebe with the go-ahead run in the top of the 10th inning as Altona shaded the Elmwood Giants 2-1 at Koskie Field in Winnipeg. Mac Batchelor got the start for the Bisons. He scattered nine hits and struckout eight in nine innings of work. Colin Walder pitched the 10th inning and recorded the win. Game two in the best-of-five semi-final goes tonight in Altona. Pembina Valley dropped an 11-6 decision to the St. Boniface Legionaires in Morden. Game two goes tonight at Whittier Park in Winnipeg.