The Wildcats (46-17) won Bracket 1 and will open the best-of-three finals Sunday. Arizona will be playing for its fourth national championship and first since 1986.
The Wildcats have won nine games in a row and are 56-0 when scoring nine or more runs since March 2010.
Leibrandt (8-3) was knocked out after 4 1-3 innings of the Seminoles' 4-3, 12-inning loss to Arizona last Friday. On Thursday, he threw 31 pitches, only 15 strikes, and his throwing error set the stage for Arizona's big first inning.
Leibrandt's struggle marked the third time in this CWS that a starting pitcher lasted an inning or less. Florida's Hudson Randall made it one inning against Kent State on Monday and UCLA's Zack Weiss was pulled after one-third of an inning against Florida State on Tuesday.
The last time so many CWS starters failed to get more than three outs was in 1995, when five got the early hook.
Arizona's six runs in the first resulted from four singles, three walks, a sacrifice fly and the three errors. No team at the CWS had committed as many errors in an inning since Miami had the same number in a 2004 game against Cal State Fullerton.
The Wildcats got their first extra-base hit of the CWS in the fourth when Refsnyder drilled a shot into the left-field bullpen for his seventh homer of the season. Seth Mejias-Brean followed with a double, and then Brown lofted a ball into the right-field bullpen for his fifth of the year.
Heyer scattered nine hits, walked three and struck out three. His 7 1-3 innings raised his nation-leading total to 153, the most of any pitcher in Division I since 2006.