[1] After missing out on the league title to the unbeaten Arsenal in the previous season, Chelsea continued spending large sums of money in order to build a squad capable of challenging for honours.

They were in their second season under the ownership of Roman Abramovich, enabling them to sign five players for more than £10 million each, including Ivorian striker Didier Drogba from Marseille and defender Ricardo Carvalho from Mourinho's former club, Porto.

The provisional fixture list was released on 24 June 2004, but was subject to change in the event of clashes with other competitions, international football, inclement weather, or matches being selected for television coverage.

A Didier Drogba debut goal for his new club (a header from a Celestine Babayaro cross) and a controlled, outside-the-box effort by Tiago were enough to ensure a 0–2 win and maintain Chelsea's 100 per cent start.

Due to the international fixtures, Chelsea did not play again until 11 September, dropping their first points of the season in a 0–0 draw at Aston Villa, but both sides were not without their chances to break the deadlock, Drogba having a penalty claim turned down and being booked for diving in the process.

Chelsea began October with yet another 1–0 win, this time against Liverpool, a Joe Cole flick from an inswinging Lampard free kick maintained their unbeaten league start.

The run, however, ended after they suffered their first and only defeat of the season away at Manchester City, with Nicolas Anelka stroking home a penalty in the 11th minute that he won himself after being felled in the box by Paulo Ferreira.

Manager Jose Mourinho maintained his optimism regarding his side's performances despite the media bemoaning Chelsea's lack of goals and style of play, particularly in contrast to the verve of unbeaten league leaders Arsenal.

Another irrefutable result, a 1–4 win away at West Bromwich Albion, pulled Chelsea level with Arsenal (but behind on goal difference) at the end of October, as the reigning champions were showing signs of faltering, narrowly earning a 2–2 draw that day.

Chelsea won the rest of their December fixtures without conceding: 4–0 vs Norwich, 1–0 vs Aston Villa, and 2–0 away to Portsmouth - as they closed 2004 sitting top of the league, five points clear of second-placed reigning champions Arsenal.

2005 began with a trip to Anfield on New Year's Day, Joe Cole once again proved the difference between the two sides, finding the back of the net five minutes after coming on as a substitute to earn a now-routine 1–0 victory for the visitors.

The Blues went on to register a 1–0 win over West Bromwich Albion at home and completed March with a 4–1 victory against Crystal Palace at Stamford Bridge as they closed in on their first league title for 50 years.

But the Blues swiftly rediscovered their touch at Stamford Bridge days later against neighbours Fulham, putting them to the sword with a 3–1 result, Frank Lampard scored the pick of the goals, a crisp low drive inside the area from Arjen Robben's cut-back on the left to restore Chelsea's lead after Collins John had equalised Joe Cole's earlier opener.

Chelsea travelled to Bolton's Reebok Stadium on 30 April 2005 with the knowledge a win and all three points would crown them Champions of England for the first time in half a century, and despite a tense and goalless first-half, the second half saw Lampard win a battle against a defender for a high, bouncing ball just outside the penalty area before making space for a fierce right-foot drive to give Chelsea the lead after an hour gone; it was a lead Chelsea doubled as they countered from a Bolton corner fifteen minutes later, Lampard picking up Claude Makélélé's through ball and rounding goalkeeper Jussi Jääskeläinen, slotting into an empty net for his second goal of the game to seal a conclusive 2–0 win and the league title for the Blues - Mourinho's first in English football - as the Blues sat top of the league with a now-unassailable 11-point lead after 35 games at the end of April 2005.

Three days later, Chelsea travelled to Old Trafford for the penultimate game of the season against third-placed Manchester United, receiving another pre-match guard of honour (customary for their remaining games since clinching the title against Bolton); and in spite of Ruud van Nistelrooy's opening goal, the Blues hit back, notching three times through Tiago, Gudjohnsen and Joe Cole late on to complete a Premier League double over United and claim a record 29th victory of the league season, moving onto 94 points.