、。
Last night, a crowd of about 80,000 people packed the stadium.
Literal
Last-night, about 80,000 people [genitive-の] spectators [subject-が] stadium [object-を] filled-up.
News-sports reporting style. うずめる ('to fill up, cram,' 'to bury') is used here figuratively — the crowd 'filled the stadium to the brim' as though burying it under people. It's the transitive counterpart of うずまる ('to be buried, be filled up'). Common figurative uses: 会場をうずめる (pack the venue), 墓をうずめる (fill the grave). Note the 'path を' is not quite right — here を is the direct-object marker, because 'to fill X with people' takes X as the object. 約 ('about, approximately') is the prefix for rounding off numbers — 約８万人 = 'approximately 80,000 people.'