More surprisingly, the former were scrapping for survival, while the latter were on the fringes of European qualification due to their influx of former World Cup winners.
Nowadays, money really has changed everything for the two clubs. While they are hundreds of miles apart, they have experienced a similar journey to the top.
An initial phase of splashing out for the world's very best talent, followed by employing the managers who boast impressive CVs, and eventually calming the spending to focus on producing their own talent.
Of course, Manchester City are still behind Chelsea in terms of stature on the global stage, and when you consider the trophy haul in the past 10 years, there is no competition.
Yet, the Blues will be wary about the speed in which the club run by Sheikh Mansour is catching up, and now under the rule of a truly inspiring Chilean who has experienced his fair share of success, the gap could tighten once more.
Here, we look at why Chelsea vs. Manchester City could be one of the key clashes of the season, as the Premier League enters a new era in 2013-14.
For a man who appears to possess an abundance of confidence and arrogance, Jose Mourinho is one of the more respected managers among his peers. And even despite his self-proclaimed boasts of being the 'Special One,' the Portuguese manager looks to be focusing on being a bit more relaxed for his second spell.
Nevertheless, the 50-year-old will know that returning to Stamford Bridge and building on what he started nine years ago will be no easy feat, especially with two of his title rivals entering the season under new managers.
Tactically astute and one of the best man-managers in the world, Mourinho has experienced success like no other in his career to date. Two Champions League titles, a historic and unprecedented Treble success with Inter Milan and, more importantly, he is the only manager to win domestic league titles in all three of the leading countries (England, Spain and Italy).
After such a disappointing end to his three-year reign with Real Madrid, when he finished the season without a trophy for the first time, he will be hungry to make amends with the Blues. He will know more than anybody the height of his task, having seen Chelsea struggle to keep up with the Manchester clubs in last season's title race.
Roman Abramovich has given Mourinho a transfer war chest to bring in the world's best talent, and has already completed the signing of German forward Andre Schurrle from Bayer Leverkusen, while Edinson Cavani is known to be at the top of his list of targets, per The Independent.
Nevertheless, he will be keen to knock both off their perch, and there's no better way to join them than to beat them first.
But after leading surprise package Malaga to within seconds of the Champions League semifinal, Manuel Pellegrini starts his adventure in England having only taken charge of clubs in the Spanish-speaking region, starting off in his native country at Universidad de Chile before moving to Villarreal.
He replaced Juande Ramos in 2009 as Real Madrid manager and actually achieved the highest win percentage of any manager (in over 20 games) in their history, winning 36 out of his 48 games in charge, totalling to 75 per cent.
Pellegrini is a very intelligent manager, and while he may not bring the most exciting football, his tenure in charge usually brings success. Luckily for their opponents, he decided to let Carlos Tevez leave for Juventus, and has since failed to secure highly-rated talent Isco from his former club Malaga.
Nevertheless, with the millions available from the club's owners Abu Dhabi United, you can assume that the Citizens will be bringing some world-class names to the Emirates Stadium. And with Pellegrini in charge, it promises to be a tough game.
As Spain's domination has spread to most quarters of World Football, it's no coincidence that two of their most gifted midfielders ply their trade for two of the strongest clubs in England.
After initially appearing that he would sign for Arsenal, per Daily Mail, Chelsea will be grateful that they managed to swoop in and steal Juan Mata from under the noses of their London rivals. The former Valencia star, who cost Chelsea a fee in the region of £26 million, has really taken the Premier League by storm, and was nominated for the PFA Player of the Year award this season.
An elegant midfielder with hawk-like vision, Mata rarely fails to impress. His awareness as he moves into pockets of space is astounding, and as well as being the Blues' main creative supply, he pitches in with the goals as well.
A total haul of 12 goals and 17 assists in his 35 Premier League appearances, the 25-year-old was largely viewed as their best player in what could only be described as a disappointing season.
Rumours have linked him with a big-money move to Barcelona, but Mata has moved to quash suggestions he could leave Stamford Bridge, per The Mirror. After all, Mata will be boosted in his quest to add the Premier League to his bulging collection of winners' medals, and under Jose Mourinho's reign, the Spain playmaker has a chance to do that by helping his side beat Manchester City.
But he will know better than anyone that his compatriot David Silva could be the man to bring the title back to the blue side of Manchester.
After excelling in his first couple of seasons at Eastlands, Silva experienced a dip in form which saw him lose his place in the Spain team to Mata.
But his unique ability to create a chance out of nowhere with a defence-splitting pass makes the £25 million investment three years ago worthwhile.
Creating chances for Sergio Aguero and Edin Dzeko will be his main task, and despite failing to impress against Chelsea last season, the 26-year-old will no doubt be motivated to change that.