A controversial and provocative figure in football, he was known for his very physical and aggressive style of defending, which saw him collect numerous cards throughout his career.

[13] He also played eight times in the season's UEFA Cup, with his competition debut coming on 20 September in the 3–0 win versus Romania's Brașov.

[16] In the following season, Materazzi made 33 appearances across all competitions, including 13 in UEFA Champions League, where he played his first match on 14 August 2002 in a goalless draw against Sporting CP.

[18] Materazzi's 2003–04 season was blighted by injuries, including one he suffered on 25 November during the 5–1 home loss to Arsenal in UEFA Champions League group stage which kept him out of action for two months.

On 5 March 2006, Materazzi scored an 89th-minute header at Roma to rescue his side a point and to break the hosts' record of 11 consecutive victories.

[35] He notably scored in the 4–3 win in Derby della Madonnina against Milan,[36] an overhead kick versus Messina and a brace away to Siena on 23 April which won the club's 15th league title with five games remaining.

[39] Materazzi missed the first part of 2007–08 season due to an injury suffered whilst on international duty which forced him to be sidelined until November 2007.

[40] Later, in February of the following year, Materazzi gave a poor display in the first leg of 2007–08 UEFA Champions League first knockout round against Liverpool, receiving a red card in the 30th minute, as Inter lost 2–0 at Anfield.

[54] Materazzi was an injury-time substitute for Inter in the 2010 UEFA Champions League Final against Bayern Munich, replacing Diego Milito who scored both of their goals in the 2–0 victory in Madrid.

[60] Materazzi's first league match of the season came later in November where he started in the derby against Milan due to the absence of Walter Samuel; he conceded a penalty in 4th minute for fouling Zlatan Ibrahimović and was later sent to hospital after a receiving a kung-fu kick in the stomach by the Swede.

[73][74] Materazzi did not choose himself to play in their opening match, a 2–1 victory at FC Goa on 15 October courtesy of a free kick from marquee player and former Brazil international Elano.

[79] On 25 April 2001, Materazzi made his debut for the Italy national team in a 1–0 friendly match victory against South Africa.

In the final tournament of the 2002 FIFA World Cup, Materazzi was used as a reserve player to back up Alessandro Nesta and Fabio Cannavaro.

[82][83] Despite a long suspension with Inter,[19] Materazzi was still called up by manager Giovanni Trapattoni for the UEFA Euro 2004,[84] where he was on the bench for Italy's first two games but started in the final group game against Bulgaria in place of the suspended Fabio Cannavaro, as Italy came from behind to win 2–1; in the first half, Materazzi was judged to have allegedly fouled Dimitar Berbatov in the area, conceding a penalty, which Martin Petrov subsequently converted.

[90] He received a red card in the round of 16 match against Australia for a foul on Mark Bresciano,[91] which ended in a 1–0 win for the Italians, and was suspended for the quarter-final against Ukraine, which Italy won 3–0.

[92] In the final against France, Materazzi fouled Florent Malouda to concede a penalty, which Zinedine Zidane subsequently scored.

Materazzi then revealed that he replied, "Preferisco la puttana di tua sorella"[96] (I would prefer your whore of a sister),[96] which resulted in the headbutt.

Alongside striker Luca Toni, Materazzi was Italy's top scorer throughout the tournament with two goals; he also won 14 challenges throughout the competition.

[100] In 2010, Zidane had said that he would "rather die than apologise" to Materazzi for the headbutt in the final,[101] but also admitted that he "could never have lived with himself" had he been allowed to remain on the pitch and help France win the match.

[102] Under Roberto Donadoni, Materazzi appeared consistently during the Euro 2008 qualifying campaign and became a starter after Alessandro Nesta's retirement.

[107] An aggressive, physical, and hard-tackling centre-back, who was also known for his tight marking of opponents,[108] Materazzi was considered to be one of the best defenders of his generation, and was highly regarded by two of the world's most respected coaches, Marcello Lippi and José Mourinho, later becoming close friends with both managers.

[109] Materazzi was lauded by his managers in particular for being a goal threat as a defender, due to his outstanding aerial ability, which made him dangerous during set pieces.

[9] In addition to these attributes, he had solid technical skills and reliable distribution, and was known for frequently playing long balls to the strikers.

[112] Due to his temper and his heavy challenges, he has been involved in several altercations with other players during matches, throughout his career[108] which drew him comparisons in the media with retired defender Pasquale Bruno.

[119] In September 2007, he released his autobiography called "Una vita da guerriero" (The Life of a Warrior) published by journalists Andrea Elefante (from Gazzetta dello Sport) and Roberto De Ponti (from Corriere della Sera).