According to Elias

July 23, 2010 – The Twins defeated the Orioles, 5-0 on Thursday, raising their record against Kevin Millwood to 9-0. That’s the most victories without a loss by any team against an active pitcher, breaking a tie with the Dodgers, who are 8-0 against Matt Cain. The Senators/Twins franchise won its first nine or more decisions against only three other pitchers: Sid Monge (their first 10, 1975-1981), Ted Blankenship (1922-1925), and Gordon Rhodes (1929-1933).