London - Anthony Joshua believes he will be up against the best fighter on the planet when he takes on Andy Ruiz Jr in his December rematch with the heavyweight world champion.
Ruiz, who was born in the United States but fights for Mexico, caused a major shock in June when he handed out a first defeat for Joshua to win the WBA, IBF and WBO crowns in New York.
In the third part of a trilogy of press conferences to promote the rematch in Saudi Arabia, Britain's Joshua told reporters in London: "My fights are the elite of the elite and are top of the crop. That little bit of motivation of fighting someone who has the skill-set and is the champion.
"It's not like I'm fighting someone as a stepping stone to a champion. We can't overlook Andy and his talent and his success in the ring as I'm fighting the best out there right now. In my opinion Andy Ruiz is the best heavyweight out there."
Former Olympic champion Joshua was knocked down four times by Ruiz before he was stopped in the seventh round on his US debut, marking one of the biggest upsets in heavyweight history.
He spoke about his desire to return to the top of the sport, adding: "Once I've got my purpose of life organised, I can do anything and that motivation will be the same.
"Put me on the street to clean graffiti off the wall, I want to make sure my graffiti cleaning is better than yours - and that's just my purpose in life.
"So motivation isn't just about boxing.
"I've got to make a few changes in my lifestyle now to correct and align them again so I align my stars so, come December 7 I'm shooting straight and I know where I'm heading.
"And that's towards those titles that at the minute are just out of reach, but sooner or later I'll be able to touch them again."
The location for December's re-match is controversial.
The Saudis have faced intense diplomatic fallout over last year's murder of dissident journalist Jamal Khashoggi in the conservative kingdom's consulate in Istanbul.
Saudi rulers have used sport as a tool to try and soften their international image.
In February, they hosted a first European Tour golf event while the world's most gruelling motor sports race, the Dakar Rally, will be held in the country in 2020.