The Dons failed to get off a final shot.
Souley Boum gave the Dons a 65-64 lead on a layup with three seconds left and then fouled McClendon beyond the 3-point line to send him to the line for his first free throw attempts of the night.
McClendon -- who finished with eight points -- put Loyola Marymount (6-10, 1-4 West Coast Conference) ahead 64-58 with 69 seconds to go before Nate Renfro countered with a jumper, Jordan Ratinho made a 3 and Boum's layup.
Boum and Frankie Ferrari led San Francisco (10-8, 2-3) with 12 points each and Ratinho scored 11.
Kevin Ollie is accusing UConn of violating his constitutional rights by firing him for cause, thereby avoiding the eight-figure payout that a termination without cause would have demanded.
Former Louisville recruit Brian Bowen will declare for the NBA draft in case the NCAA does not allow him to play at South Carolina.
Kentucky's Wenyen Gabriel, who averaged 6.8 points and 5.4 rebounds during his sophomore season, has declared for the NBA draft.