string having alphabets and numbers convert uppercase to lowercase except first letter using javascript

Question

I would like to know how to convert the string to lowercase except first letter

I have tried below code but converts all to lowercase, can help how to convert uppercase to lowercase except first letter using javascript.

var str1 = '1 WOOD AVE'
var str2 = '22 CROSS STREET'

Tried
var result = str1.charAt(0).toUpperCase() + str1.slice(1).toLowerCase(); // not working

Expected Output

1 Wood Ave
22 Cross Street