Chelsea manager Jose Mourinho has stoked the fire ahead of the new Premier League season by slamming Manchester City and Manchester United's recent title wins.
City spent close to £1bn before claiming the league title on the final day of the 2011/12 season while last term United, in Sir Alex Ferguson's last campaign as manager, finishing 15 points ahead of the chasing pack to claim a record 20th domestic crown.
Mourinho twice won the league title during his three-and-a-half year spell at Chelsea from 2004-2007, setting the highest points total in Premier League history of 95 in his first season in charge.
The Portuguese boss has watched from afar as the Manchester pair have sought to dominate the league in recent seasons, but the returning Chelsea manager is far from convinced by either's recent title success.
"You think Manchester United won the Premier League because they were an unbelievable team? I don't think so," Mourinho said prior to the club's opening game against Hull City.
"I think the other contenders didn't have a very good season and the same the season before.
"City won the title in the last second of the competition, were they an extraordinary team? I don't think they were. The others teams make so many mistakes and they won the competition.
He added: "In our year we faced a fantastic Arsenal team who won almost every game and were champions without one single defeat. You had a Chelsea who had record points in the Premier League.
"The Man United who won the (2006/07) league after our double had an unbelievable season.
"I think the champions in other seasons weren't magnificent, especially in the last two seasons I feel not. I feel they were champions as consequence of many things not because they were brilliant.
"The other big teams made too many mistakes.
"It's difficult to win points in the Premier League but last year in the first part of the season Manchester United were playing matches that the other teams were losing points.
"Sometimes you win because you are tremendous and sometime you win because you are the best.
"Wenger speaks of the six candidates and I agree with him. This season we don't see a team who can destroy the opposition and get 95 points."
Mourinho rejoins a Chelsea side who have won the Champions League and Europa League in successive seasons under Roberto di Matteo and Rafa Benitez, continental success the former Real Madrid was unable to achieve during his first spell in west London.
The 50 year old has indentified the Champions League as a priority for the new season but admits a repeat of last season's victory in the Europa League would represent a failure.
"If I win the UEFA Cup (Europa League) I think it is a failure because if we win the UEFA Cup it is because we are out of the group phase of the Champions League," Mourinho said.
"It can happen. I cannot say my players or my club want to win the UEFA Cup, we want to win the Champions League and we go step by step.
"UEFA Cup is something we don't even want to play, they did well last season and that's good, but we don't want to play."