preg_replace on the actual match ( index 1) instead of whole string : <p>Consider</p>

<pre><code>preg_replace('/(lets go).*/', "going", "lets go somewhere")
</code></pre>

<p>It will output: "going", I want "going somewhere". </p>

<p><code>preg_replace</code> seems to replace using the first match which is the whole string "lets go somewhere". How can I make it ignore index 0 and only target index 1?</p>
