The 14th-ranked Lobos will meet Nevada-Las Vegas in the title contest after the Rebels knocked off Colorado State 75-65.
New Mexico built a 21-point lead early in the second half and ran their record to 28-5. The Aztecs shot a mere 31 percent from the field, made just five free throws and went 5-of-21 from 3-point range.
Cameron Bairstow added 16 points and 11 rebounds for New Mexico, which will be trying for its second consecutive tournament championship.
Chase Tapley and Xavier Thames both had 14 points for San Diego State (22-10).
New Mexico is the No. 1 seed in the tournament and it has been six seasons since the top seed has won the event.
Katin Reinhardt scored 21 points in leading UNLV, which won its third in a row and its eighth out of nine.
The Rebels shot just 41 percent from the field, but they hit 15 more free throws than did Colorado State.
New Mexico and UNLV split their two regular-season encounters.