How to combine two divs that have the same class - jQuery

Question

I have a div structure like this

<div class="items">
    <div class="itemRow">
        <div class="item">
        <div class="item">
        <div class="item">
    </div>
    <div class="itemRow">
        <div class="item">
        <div class="item">
        <div class="item">
    </div>
</div>

How can I make them merge/combine the two divs "itemRow"? to be like this

<div class="items">
    <div class="itemRow">
        <div class="item">
        <div class="item">
        <div class="item">
        <div class="item">
        <div class="item">
        <div class="item">
    </div>
</div>

using jQuery

Answer 1

Try

var $rows = $('.items .itemRow');
$rows.first().append($rows.not(':first').children())
$rows.not(':first').remove();

Demo: Fiddle