Identifying the Lowest grade for a student

Hi Folks,
Need some help.
I have a list

[Column 1 Col2 Col3
JOHN 5 2
JOHN 10 2
JOHN 2 2
JOHN 20 2
JAMES 28 4
JAMES 4 4
JAMES 18 4
JULIE 5 0
JULIE 6 0
JULIE 0 0
JULIE 3 0
I want the lowest figure for each person to appear in the third coulmn (I have the data in the first two columns)

I would use a formula like the one below - to count the number of instances the individual's name appears
COUNTIF($D$6:$D$17727,$D$6:$D$17727)

Is there something similar that will let me produce the lowest number in the 3rd column ?
Thank You