Florida (25-6) broke open a tight game that was 18-17 midway through the first half with a run that had the Gators up 50-29 2 minutes into the second half.
Florida goes against Alabama (21-11) in the tournament semifinals Saturday. Alabama advanced with a 58-48 decision over Tennessee.
The other semifinal game will send Vanderbilt against Mississippi.
Vanderbilt added to Kentucky's uncertainty over an NCAA Tournament bid by downing the Wildcats 64-48 and Mississippi pulled off a thrilling 64-62 win over Missouri.
Murphy was 11-of-15 from the field, including 5-of-7 from three-point range. His 12 rebounds also marked a game-high. Scottie Wilbekin produced 16 points on 6-of-8 shooting for the Gators.
Charles Carmouche, with 14 points, was the only LSU player in double figures.
Alabama did not have a field goal in the final 5 minutes but was able to put Tennessee (20-12) by hitting 6-of-8 free throws down the stretch. Tennessee, however, didn't have a basket in the final 2 minutes.
Levi Randolph, who had three of the late free throws, scored 15 points and Trevor Releford 14 for Alabama. Josh Richardson led Tennessee with 16 points and Jarnell Stokes had 12 points and 13 rebounds, eight of which came on the offensive end.
Vanderbilt took a 14-point halftime lead after shooting 59 percent in the first 20 minutes and never let Kentucky closer than 10 points the rest of the way. Dai-Jon Parker scored 12 for the Commodores (16-16) and Kevin Bright delivered 11.
Derrick Millinghaus hit a jumper with 5 seconds to go for the winning points in Mississippi's comeback win over Missouri. Millinghaus also tied the contest with 30 seconds remaining by hitting a 3-pointer.
Missouri led by as many as 13 points in the second half. Marshall Henderson led Mississippi (24-8) with 27 points.