CAMBRIDGE, Mass. — Penn swimmer Lia Thomas won the 500-yard freestyle race at the Ivy League championships Thursday night, accelerating past her competitors to establish a new record for Harvard University’s Blodgett Pool. The natatorium boomed with cheering athletes and fans as Thomas swam neck and neck with her competitors for the first part of the race. Around the halfway mark, Thomas took a significant lead and finished in 4 minutes, 37.32 seconds, about three seconds off her personal best, and edging the pool record by three-tenths of a second. In second place was Penn sophomore Catherine…