[2][10] In the summer of 1929, at age 10, he threw himself into the river Adda to save the life of a boy four years his junior from drowning: his name was Andrea Bonomi, the future football player and captain of Milan.

[7] In 1939 he was called up to join military service in the Royal Navy, in the port of Venice; he spent a few months on the ship, aboard the destroyer Confienza, and was later moved to the Compagnia del Porto.

He worked in Lingotto and reported as a FIAT worker essential to wartime production, to avoid participating directly in the Second World War.

The players were not considered professionals and officially held other jobs; in the aftermath of the war, Mazzola owned a sports shop in Turin, where he sold footballs that he manufactured personally.

He made his debut in Serie A on 31 March 1940, in a 1–0 defeat away to Lazio, entering as a substitute for the centre forward Francesco Pernigo, and kept his place in the starting lineup on his own merits.

He played in all five of the remaining league games, often in the middle of the attack, creating a goal on the penultimate day against Bari, guaranteeing Venezia safety from relegation.

The partnership of both attacking midfielders (mezzala in Italian) was based on Loik's stubborn generosity and the Mazzola's rare talent.

[7] In early July 1942, he transferred to Torino for one million and 250 thousand lira, a figure that was criticised by the press, and allowed Venezia to restore all its debts.

Both Mazzola and Loik played poorly because of their imprecision and their lack of understanding and were considered responsible for the 1–0 defeat Torino suffered in Milan against Ambrosiana-Inter.

Mazzola, unlike many of his fellow players, who had returned to play with their home teams, stayed in Turin and, together with his other teammates, and began to train and participate in some games.

In this season, Mazzola would also begin rolling his sleeves up to mark the quarto d'ora granata ("the maroon quarter-hour") when the team needed the extra push.

Mazzola and Loik would constitute the two points of greatest strength of the formation, with Torino winning their fourth overall Scudetto at the end of the season.

Various interpretations of this event exist: besides the simple justification that the Mazzola wanted to rest, as he was tired and struggling with injuries, there were also rumours that he intended to end his relationship with Torino and move to Internazionale.

A few days before the start of the new season, scheduled for 19 September 1948, six Torino players, including Mazzola, did not return due to a contract dispute.

On 30 April, Torino drew 0–0 at the San Siro against Inter; Mazzola, due to a strong sore throat with high fever and a form of angina, did not take part in the match.

Ferreira and Mazzola had met in a restaurant in the afternoon, and discussed the match that Benfica would dedicate to the Portuguese, with proceeds donated to charity.

The funeral, attended by over half a million people, was held on 6 May; the bodies were brought to Palazzo Madama, from where the procession departed, continuing to the Duomo.

On the same day the FIGC proclaimed Torino champions of the 1948–49 season, four rounds before the end, approving the proposal of Inter, Milan and Juventus.

[14][15] Mazzola is considered one of the best football players of all time, and perhaps the first modern all-around footballer; a well-rounded, versatile, and hardworking player, he was capable of playing in any position on the pitch, and was known for his strong character and winning mentality, as well as his ability to lead his teammates to victory with his charismatic presence and leadership (Mazzola was famous for raising his shirt's sleeves when his team was not playing well as a signal to his teammates and the fans).

[3][16][17] Mazzola was a quick, strong and energetic midfielder, with excellent technical qualities and dribbling skills, as well as notable stamina, positional sense, vision, creativity, and accurate shooting and passing ability with both feet.

Although he was usually deployed as an attacking midfielder, he was also capable of playing in more offensive roles, as a main forward, as a winger on either flank or as an inside or supporting striker.

Despite his small stature, he excelled in the air, due to his power, timing, heading accuracy, and elevation, which allowed him to beat larger players for the ball.

[20] José Altafini, a forward who won the 1958 World Cup with Brazil and also played for Italy, is called "Mazzola" in his home country due to his resemblance to Valentino.