deleting a character

Hi I am having problems deleting a character

Basically I want to recognize lines with > and then delete a character that is seperated by a space. Here is an example of how the file looks like.

>chr86 86

Heres what I want it to look like:

>chr86

thanks

Phil

echo '>chr86 86' | sed 's/^\(>[^ ]*\).*/\1/'

echo '>chr86 86' |awk '{/^>/} {$2=""}1'