The 2021-22 UEFA Champions League kicked off with a riveting round of Matchday 1 fixtures.
Among the notable results, Manchester United stumbled to a reverse at Young Boys, and Barcelona lost at home to Bayern Munich. Elsewhere, defending champions Chelsea, Manchester City, Juventus and Real Madrid opened their campaigns with wins.
There were a few noteworthy individual performances during the gameweek. Sebastien Haller and Christopher Nkunku impressed by scoring hat-tricks, the former doing so on his competition debut.
In the three-decade-old history of the Champions League, 104 different players have scored hat-tricks in the competition. However, only ten of them have done so on their Champions League debut. So without further ado, let's have a look at the ten players:
#10 Sebastien Haller (Ajax) - 2021-22
Sebastien Haller made his Champions League debut an occasion to remember, as the 27-year-old scored four goals in Ajax's 5-1 win at Sporting Lisbon.
The Cote d'Ivoire forward joined legendary Dutch striker Marco van Basten as the only player to score a quadruple in their first Champions League game.
Haller set the ball rolling as early as the second minute before doubling Ajax's advantage just nine minutes into the night. He scored the third six minutes into the second half, becoming the tenth player to score a hat-trick on his Champions League debut.
Not content with that, Haller scored another 12 minutes later to help the former winners open their campaign with a resounding win on the road.
#9 Mislav Orsic (Dinamo Zagreb) - 2019-20
Mislav Orsic scored three times against tournament debutants Atalanta in a 4-0 home win for Dinamo Zagreb in the 2019-20 Champions League.
Orsic's goals made Croatia the 17th different nation and Dinamo Zagreb the 47th different club to register a hat-trick in the Champions League. The midfielder scored twice in the first half before completing his hat-trick midway through the second.
Orsic recently scored another European hat-trick, scoring three past Tottenham Hotspur in last season's Europa League. That made the 28-year-old only the second player to score a European hat-trick against Spurs.
#8 Erling Haaland (Salzburg) - 2019-20
Erling Haaland took to the Champions League like a fish to water when the then 19-year-old scored thrice in Salzburg's 6-2 win over Genk.
That made Haaland (19 years, 58 days) the third-youngest player to score a Champions League hat-trick. Only Real Madrid legend Raul (18 years 113 days) and Wayne Rooney (18 years 340 days) were younger than the Norwegian when they scored thrice on their Champions League debut.
Haaland is the third Norwegian player to net a Champions League hat-trick. The teenager's three-goal haul made Salzburg the 46th different club and the first from Austria to register a hat-trick in a Champions League game.
Now at Borussia Dortmund, Haaland is already up to 20 goals in the competition, becoming the youngest and quickest player to reach the landmark.
Haaland has scored ten goals in each of his last two campaigns in the competition. He opened his account for the season by scoring in Dortmund's 3-2 win over Besiktas on Wednesday.
#7 Yacine Brahimi (Porto) - 2014-15
Yacine Brahimi provided the 91st hat-trick of the Champions League when he scored three goals for Porto against BATE Borisov in 2014-15. That made Brahimi the first Algerian player and Porto the 42nd different club to score a hat-trick in the competition.
He scored twice inside the opening 32 minutes. Brahimi then completed his hat-trick 12 minutes into the second half as Porto won 6-0 on the night.
In the process, the 24-year-old Algerian became the youngest African player after Nigeria's Yakubu (19 years) to score three goals in a Champions League game. Incidentally, Brahimi's hat-trick was the first by a Champions League debutant in five years.
In 34 subsequent games in the competition since his hat-trick, the winger has scored only five more times though.
#6 Grafite (Wolfsburg) - 2009-10
Grafite became the eighth Brazilian player to score a Champions League hat-trick when he netted thrice for VfL Wolfsburg against CSKA Moscow in a 2009-10 game.
It was the 60th hat-trick in the competition as Wolfsburg became the 39th different team to register a hat-trick in the competition. The Brazilian striker scored all three goals as the then Bundesliga champions opened their campaign with a 3-1 win over CSKA Moscow.
Grafite is the oldest Brazilian and one of a handful of players aged thirty or above to score three times in a Champions League game. Those three goals proved to be his only strikes in five games in the competition.
#5 Vincenzo Iaquinta (Udinese) - 2005-06
Vincenzo Iaquinta scored the 48th hat-trick of the Champions League in Udinese's 3-0 win over Panathinaikos in a 2005-06 group game.
The 2005 World Cup winner is the fifth and latest Italian player to score three times in a Champions League game.
Iaquinta's three-goal haul made Udinese the 35th different club to score a Champions League hat-trick. He has scored eight goals in the Champions League in 12 games, with four of them coming for Juventus.
#4 Wayne Rooney (Manchester United) - 2003-04
Wayne Rooney is the first Englishman to score a hat-trick on his Champions League debut. He did so when he netted thrice in Manchester United's 6-2 win over Fenerbahce in 2004-05.
In the process, the then 18-year-old became the second-youngest Champions League debutant to score a hat-trick. Rooney also provided an assist on the night as United recorded a big win at Old Trafford.
That would be his only hat-trick in the competition. Rooney scored 30 goals in 85 Champions League games, all for Manchester United. His last goal in the competition came against CSKA in 2015
#3 Yakubu (Maccabi Haifa) - 2002-03
Yakubu scored a hat-trick on his Champions League debut in 2002-03. The Nigerian striker scored thrice for Maccabi Haifa in their 3-0 home win over Olympiacos in a group game. In the process, the Nigerian became the fourth teenager to score a Champions League hat-trick.
It was the 33rd hat-trick in the competition and the first by an African player. Maccabi Haifa became the first club from Israel to register a Champions League hat-trick.
Incidentally, Yakubu scored only two more times in the competition, all for Maccabi Haifa.
#2 Faustino Asprilla (Newcastle United) - 1997-98
Faustino Asprilla provided the 12th hat-trick of the Champions League. He scored thrice in Newcastle United's 3-2 home win over Barcelona in a 1997-98 group game.
The goals made Asprilla the first South American since Romario to score thrice in a Champions League game. In the process, Newcastle became the second English club, tenth overall, to score a Champions League hat-trick.
Asprilla and Andriy Shevchenko (also in 1997-98) were the only players to score a Champions League hat-trick against Barcelona. This is before Kylian Mbappe joined them almost two decades later.
Those three goals would be Asprilla's only strikes in the Champions League, as he went scoreless in four other games in the competition.
#1 Marco van Basten (AC Milan) - 1992-93
AC Milan legend Marco van Basten was the first player to score a hat-trick on his Champions League debut. He provided the third-ever hat-trick in the Champions League when he netted all four goals in Milan's 4-0 win over IFK Göteborg in a 1992-93 group game.
For almost three decades, the legendary Dutch striker remained the only player to score four times in their first Champions League game. That was until Sebastien Haller joined him by scoring a quadruple against Sporting Lisbon on the first matchday of the 2021-22 season.
With his quadruple, Van Basten joined compatriot Juul Ellerman as the only Dutchman to score three goals in a game in the competition. Ellerman was the scorer of the first Champions League hat-trick. Thanks to Van Basten's strikes, Milan beat Gotheborg 4-0 at home in the first-ever Champions League season.
It would be seven more seasons before another player - Simone Inzaghi - would score four times in a Champions League game.