Oracle Analytics Window Function -

if have data so:

mydate    level 01jan2016 5.1 02jan2016 6.2 03jan2016 8.0 04jan2016 5.8 

how can use windowing function return date highest level ? thinking:

select max(mydate) on (order level) x

... doesnt seem work. tried using partition still no luck. want max(level).

select mydate, level (select mydate, level, row_number() on (order level desc) rn x) rn = 1