as soon as vs as early as

[Carrieleigh]

In most cases, I clearly understand the difference between as soon as and as early as, but this one is tripping me up.

Pain relief was evident as soon as 30 minutes.
Pain relief was evident as early as 30 minutes.

I am leaning toward the first, but I am keep questioning it. I appreciate any insight.

Thank you.

 

[EnglishFix]

I think the second one sounds better.

I think it could also be...
Pain relief was evident in as early as 30 minutes.