Brought in by the club's general manager Zvezdan Terzić, the nineteen-year-old defender struggled initially, reportedly even drawing ire from his OFK team-mates due to static posture and clumsy defensive reactions.

Ivanović contributed some outstanding performances to Lokomotiv's title challenge that ultimately fell short at the end of the season as head coach Muslin got fired and replaced by Oleg Dolmatov.

Reportedly, Ivanović, who had not played competitive football in weeks, failed to impress in training, showing a lack of pace and fitness that was especially evident when matched up against club's forwards, even youth prospects such as 16-year-old Frank Nouble.

[17] Ivanović soon went on to make his Premier League debut, starting against Aston Villa and playing the full 90 minutes at Stamford Bridge on 5 October, a match Chelsea won 2–0.

Ivanović, however, was still far from securing a regular spot; he sat out the following five league matches, only receiving a single substitute appearance in the 85th minute away at Hull City with the contest already decided at 0–3 when Scolari sent him on to replace José Bosingwa.

It would be Ivanović's starting performance at right back in League Cup against the second-tier Championship side Burnley on 12 November that convinced the Brazilian manager to give the Serb another look.

It would be the performance at home versus Arsenal on 30 November, however, that lowered Ivanović's stock in Scolari's eyes again; after being up at half-time, the Blues lost the contest 1–2 courtesy of Robin van Persie's second half brace.

Chelsea were in a poor run of form, culminating with a 2–0 loss away at Liverpool followed by a goalless home draw versus lowly Hull City, all of which led to Luiz Felipe Scolari's removal on 9 February.

It was the player's first league appearance in more than three months for the club, and it happened only days after he scored the winning goal for the Serbia national team in a 2010 FIFA World Cup qualifier away at Romania.

[22] Beginning the season under yet another new manager in Carlo Ancelotti, Ivanović's fourth in his first 18 months at Stamford Bridge, the Serb made his first start in the Community Shield against Premier League champions Manchester United.

[23] In mid-August, Ivanović made his first Premier League appearance of the season against Sunderland, which Chelsea won 3–1 through goals from Michael Ballack, Frank Lampard and Deco.

On 22 December, a week before the opening of 2009–10 winter transfer window, he was placed on the cover of Marca, the influential Spanish sports tabloid that maintains strong links to Real Madrid.

In the Champions League second round first leg away at José Mourinho's Internazionale, the eventual winners of the competition, Ivanović ran a majority of the pitch before passing to Salomon Kalou, who scored Chelsea's equaliser.

[29] Early in 2011, Ivanović scored his first goal of the year on 15 January 2011, in a 2–0 home win in a Premier League match against Blackburn Rovers at Stamford Bridge, with a shot from close range.

[citation needed] Ivanović scored a headed goal in the 42nd minute of Chelsea's 5–0 Champions League group stage win over Belgian club Racing Genk at Stamford Bridge.

[citation needed] Ivanović scored the winning goal in the Champions League round of 16 on 14 March 2012 to complete the turn around against which was decisive extra time winner against Napoli, which Chelsea won 4–1 and 5–4 on aggregate at Stamford Bridge.

He then went on to help Chelsea overcome Benfica in the quarter-finals and beat favourites Barcelona in the semi-finals, though he received a second yellow in the second leg and so missed the final against Bayern Munich due to suspension.

[40][41] Ivanović again displayed his recent goal-poaching prowess and opened his goalscoring account for the calendar year on 5 January 2013, adding a third goal to the scoreline in a third round FA Cup victory against Southampton.

In Paolo Di Canio's debut as Sunderland manager on 7 April, Ivanović diverted David Luiz's long range shot past the outstretched arms of Black Cats goalkeeper Simon Mignolet, securing a 2–1 victory for Chelsea.

[44] The goal was the Serb's eighth of the campaign in all competitions, and first in the Europa League, and secured a second successive European title for the London club[45] and the 11th major trophy of the Roman Abramovich era.

[50] Replays showed that as the two tussled for an incoming cross from Steven Gerrard, which was deflected out by Ryan Bertrand for a corner, Suárez dug his teeth into the right arm of Ivanović.

[60] On 1 March he started – and played the full 90 minutes – in the League Cup final against Tottenham Hotspur, helping his side to a 2–0 win for their first piece of silverware of the season.

[citation needed] Although suffering a minor injury in the beginning of pre-season,[69] Ivanović returned during Chelsea's tour of the United States and continue to rotate throughout the games with young right back Ola Aina.

[73] Ivanović went on to score his last goal in his final appearance for Chelsea in their 4–0 home victory against Championship side Brentford in the FA Cup, driving a low, hard shot past goalkeeper Dan Bentley.

[83] Ivanović received his first cap on 8 June 2005 in Toronto, Ontario, Canada, when Serbia and Montenegro played a friendly against Italy, coming on as a 77th-minute substitute for his club teammate Marko Baša in an eventual 1–1 draw.

Looking back on the beginning of the player's accomplished career, OFK Beograd's general manager Zvezdan Terzić, who signed Ivanović at age nineteen from the lower-league FK Srem, stated: "I noticed him in Sremska Mitrovica, witnessing physical dispositions no other white footballer had.

He is a competitive animal with a big heart.A tall, brave, and physical player, Ivanović is well known for his aerial ability, which when combined with his sheer strength, has seen him score numerous crucial goals during his career.

Uncharacteristically for a defender, he possesses an adept finishing ability, with former Chelsea manager José Mourinho often using the Serbian as a striker when the team are in desperate need of a goal.

His unforgiving style of defending has led him to become a feared opponent in the Premier League, with Manchester City attacker Raheem Sterling claiming, "The scariest player to play against was Branislav Ivanović.

[92][94] Moreover, he is also known for his leadership qualities, having captained his nation, with former teammate John Terry describing him as a "legend" upon his departure from the club, and as an "[u]nbelievable defender for us over the years and a great and big character and presence in the dressing room."