[7] He was used sparingly in his first year, playing in only 13 Primeira Liga games; he made his UEFA Champions League debut on 16 September 2003 in a 1–1 away draw against FK Partizan,[8] appearing in a further seven matches in the club's victorious campaign.

The campaign ended on a sour note as, in May, he was at the wheel of his jeep when excess speed and wet road conditions led to a serious accident, with the vehicle skidding off the motorway and rolling down an embankment before bursting into flames.

[16] All escaped alive, but one of them, Sandro Luís (player of modest Grupo Desportivo os Minhocas), had to have his left foot amputated as a result of the accident, which took place in Valongo; years later, Bosingwa was made to pay €175.000 in compensation.

He put pen to paper on a three-year deal[20] and joined the London club after Euro 2008, along with Portugal national team boss Luiz Felipe Scolari and fellow international Deco; on 16 July he was officially presented with the number 16, but switched to No.

[26][27] Bosingwa was banned for three European matches as a result of comments he made about the refereeing of the Champions League semi-finals second leg clash against FC Barcelona (6 May 2009, 1–1 draw in England) on Portuguese television.

[36] On 23 October 2011, in a game against Queen's Park Rangers, Bosingwa was controversially sent off by referee Chris Foy after a challenge with Shaun Wright-Phillips, as Chelsea went on to lose 1–0 away, with Didier Drogba also being dismissed for foul play.

[37] In late November, he started in the Champions League group stage match at Bayer 04 Leverkusen as left back, playing out of position to replace injured Ashley Cole in an eventual 2–1 defeat.

[40] With the back four being commended for their ability to keep the strong opposing forward line at bay, he himself received plaudits for his efforts against winger Franck Ribéry;[41] Shortly after, however, along with teammates Drogba and Salomon Kalou, he was told he could leave once his contract expired the following month.

[51] Due to his consistent performances at club level, Bosingwa received his first call-up to the Portugal national team in May 2007, for a UEFA Euro 2008 qualifier away to Belgium,[52] replacing Miguel in the second half of the 2–1 win on 2 June.

Although he played for the country at under-21 level, he was also eligible to represent the Democratic Republic of Congo if he made an application to apply in 2004; subsequently, he was invited by the African nation to appear for them in the 2006 World Cup qualifying campaign.