One protester cried "scumbag" as Mr Key entered his vehicle.
"Wasted opportunity"
Mr Key said he would to return Te Tii Marae next year despite the verbal barrage he was subjected to.
When he was Leader of the Opposition, Mr Key had criticised then-Prime Minister Helen Clark for stopping the visits to the Lower Marae after she was jostled one year.
"I come to pay my respects to the elders of the marae and at the end of the day I'm just not a Prime Minister that cuts and runs."
He said the decision was made to halt his speech and leave simply because he could not be heard.
"I didn't feel in the slightest bit threatened. There was a very heavy police presence.
"I'm not angry about the situation. I just see it as a wasted opportunity."
He had expected protesters and said they were "familiar faces" - including the Popata brothers, who jostled him in 2009.
A handful of protesters rushed onto the marae when Mr Key first arrived at 10am, knocking aside members of the media as they moved. Two photographers, including one from the Herald, were seen bleeding after the rush.
It is believed the injuries were not caused by deliberate attacks.
"Shame, shame, shame"
Other politicians who arrived to tense scenes at Waitangi included Treaty Negotiations Minister Chris Finlayson, New Zealand First leader Winston Peters, and Northland MP Mike Sabin.
Officials tried to maintain order as one group of protesters chanted loudly against deep sea oil drilling.
Kaumatua John Komene's earlier plea to respect the official powhiri went ignored by the protesters. As one man held aloft a sign declaring Bill English New Zealand's "filthy Minister of Finance", Komene gently asked him, in Te Reo, to show respect.
Across the road, approximately 30 Mana Party supporters stood facing a police cordon at a hedge on the marae's edge. They chanted slogans at Maori Party co-leader Dr Sharples, who arrived at 9.45am, and drowned out most other noise with a repeated cry of "shame, shame, shame."
Mana's Annette Sykes addressed the group with a loud hailer, saying she wished to particularly thank the party's Pakeha supporters. She continued to speak as the Prime Minister arrived.
Veteran activist Titewhai Harawira arrived well before the proceedings. The elderly mother of Mana leader Hone Hawawira was looking frail and had to be helped by family as she moved on her crutches. Mrs Hawawira was escorted by Superintendent Wally Haumaha, the police's national manager of Maori-Pacific ethnic services.
Despite the commotion, the actual number of people around the marae appeared to be down from 2011.
Hot air rushes out
The mood turned to calm after the Prime Minister's exit, with delegations from Labour and the Greens finding a more cordial atmosphere than Government representatives had experienced earlier.
Activist Tame Iti and the Maori Party's Te Tai Tonga MP Rahui Katene accompanied Labour leader David Shearer onto the marae after 11am, by which time most of the protesters had left. Mr Shearer was joined by Labour MPs Parekura Horomia, Shane Jones, and Andrew Little.
Co-leader Russel Norman and second-term MP David Clendon represented the Green Party.
