Can't filter out column when that column is used by -groupby

Here is my elaborate program:

get-eventlog -LogName Application -Newest 5 | Format-Table -GroupBy Source

My goal is to GroupBy Source, but not SHOW source columns in each group because its redundant information. Now I’m aware of select-object and -excludeproperty but it doesn’t seem to work unless I manually specify the columns to select first. If I do that, then when it pipes to format-table from Select, ‘Source’ no longer exists and therefore cannot be grouped anymore. Is there a way to do this? I basically want to group by a property but not show that property

get-eventlog -LogName Application -Newest 5 | Format-Table -GroupBy Source -Property Index, Time, EntryType, InstanceID, Message

Shoot, that was easy. thanks