.class {
  background-image: url('/path/to/image.png');
  background-image: -webkit-radial-gradient(top, ellipse cover, #f9f9f9 0%,#eaeaea 100%);
}

<div class="background-gradient">
  <div id="first-background"></div>
</div>

.background_gradient {
  position: relative;
}
.background_gradient:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index:-1;
  background: -webkit-radial-gradient(top, ellipse cover, #f9f9f9 0%,#eaeaea 100%);
}
#first_image {
  background: url(images/img01.png);
}
#second_image {
  background: url(images/img02.png);
}
#third_image {
  position: relative;
  background: url(images/img03.png);
}