So the correct answer, for last win over a Top 10 Big East opponent in a true road game is ... 9 years.
Credit to Buzz Williams' Spillproof Chiclets Cup
Marquette has beaten one ranked team away from home this year (then-#22 LSU)
Marquette hasn't beaten a ranked team in a true road game since beating then-#9 Wisconsin in Madison on December 3, 2011 (0-9 since).
Marquette hasn't beaten a Top 10 team in a true road game in the same time frame (0-6 since).
Marquette hasn't beaten a ranked Big East opponent away from home since beating then-#14 UConn on February 24, 2011 (0-11 since).
Marquette hasn't beaten a Top 10 Big East opponent away from home since beating then-#10 Villanova in the Big East Tournament on March 11, 2010 (0-11 since).
Marquette hasn't beaten a Top 10 Big East opponent in a true road game since beating then-#6 Pittsburgh on January 21, 2007 (0-13 since).
