NEW YORK -- With only eight days until SummerSlam, Randy Orton made good on his promise to hurt WWE Champion John Cena and served notice in front of a national TV audience that he would show no mercy in his efforts to regain championship gold.

As The Champ was busy making Carlito tap out to the STFU in their Big Apple Showdown on Saturday Night's Main Event, Orton sprinted to ringside and attacked Cena from behind. Tossing Cena outside the ring and then headfirst into the ringside steps, Orton coldly set up a steel chair and waited like a coiled snake, ready to strike.

When Cena staggered to his feet, Orton pounced. He unleashed a vicious RKO on the champion, smashing Cena's head into the waiting steel chair. The Madison Square Garden crowd exploded as Orton stood above the unconscious champion and the mangled chair. (WATCH)

"What you saw out there was a message that I was sending to John Cena, and it was loud and clear -- loud and clear," Orton said after the attack. "John Cena has just seen the beginning of what he's going to get from Randy Orton at SummerSlam."

The Champ's fans were horrified at the Legend Killer's show of brutality. But to look back at the destruction Orton has unleashed on the careers of WWE Superstars and legends alike, his callous attack on Cena came as no surprise. WWE officials poured to ringside to stop him from inflicting further damage, separating Orton from his victim.

Will Cena be able to bounce back from this devastating blow at SummerSlam? Will The Champ be 100 percent for his WWE Championship defense at SummerSlam against the youngest World Heavyweight Champion in history? Or will his nearly year-long championship reign, much like his night at Madison Square Garden, come to a crashing halt at the hands of the Legend Killer?

Check out Orton's Skull t-shirt...