Nathan Coulter-Nile’s 92 against the West Indies was the highest score by any No 8 batsman in the World Cup.
Here are the list of all such scores above 40:
It can be seen that the record score at No 8 was earlier 72* by HH Streak in 2003.
The previous highest score by Australia was somewhat further down at 43 by BJ Haddin in 2015. Nearby there is 42 by CH Morris of SA in 2019.
The best by India is a mere 28 by NR Mongia in 1999.