Solution to my query:
search_string|streamstats max(LoadTime) as max_time by Application|sort +Application -LoadTime|streamstats first(max_time) as max_time by Application|where LoadTime=max_time|table Application,max_time,User
If you need to use stats function like sum as well on any of the field, you can do as follows:
search_string|eventstats sum(LoadTime) as TotalTime by Application| streamstats max(LoadTime) as max_time by Application|sort +Application -LoadTime|streamstats first(max_time) as max_time by Application|where LoadTime=max_time|table Application,max_time,User,TotalTime
... View more