Iirc The English occupied the high ground and although tired and exhausted they were in no danger of ‘losing’ … until the Normans attacked again (having been repelled many times), then pretended to retreat in disarray, causing the common troops to charge down the hill after them believing victory was there’s, where they were severely battered by the ‘retreaters’ and the Norman cavalry which could be deployed on the flat lower ground. Harold was left with 1/3 of his troops gone…and the press of the next Norman attack with vastly improved superiority of numbers … and having seen 1/3 of their number massacred, having fought continuously for most of the day and the knock-on effects of the amazing March from Stamford bridge… and then Harold being injured…
still, it united England and we never suffered a successful conquering invasion ever again.