Sign it, seal it, deliver it.

After Rory MacDonald's untimely injury threw the UFC 158 fight card into disarray, the final piece of the puzzle has now been snapped into place for the upcoming "St. Pierre vs. Diaz" pay-per-view (PPV) on March 16, 2013 at the Bell Centre in Montreal, Quebec, Canada.

You can thank Nate Marquardt.

The "Great" one stepped in on short notice to fight Jake Ellenberger, who was left without a date to the big dance when Johny Hendricks abandoned his post for a crack at Carlos Condit, MacDonald's original opponent, according to our brethren over at MMA Fighting.

See how that unfolded here.

Marquardt (32-11) is looking to bounce back from a five-round ass whooping at the hands of Tarec Saffiedine, who stripped him of the Strikeforce welterweight title last month in Oklahoma. The unanimous decision loss slammed the brakes on consecutive wins, dating back to his judges' nod over Dan Miller is his last Octagon appearance nearly two years ago.

But that was at middleweight.

Ellenberger (28-6) returned to form last October by out-pointing the venerable Jay Hieron at UFC on FX 5. His victory over "The Thoroughbred" got him back into the win column after Martin Kampann snapped a six-fight winning streak and bounced him from the division title hunt.

Does a big win for "The Juggernaut" get him back into the mix?

UFC 158 will feature the long awaited welterweight championship showdown that pits reigning 170-pound king, Georges St. Pierre, in the main event against former Strikeforce head cheese and resident Stockton bad boy, Nick Diaz.

For the latest and greatest UFC 158-related news and notes check out our complete event archive right here. And to check out the latest "St. Pierre vs. Diaz" fight card and rumors click here.