#4 Cristiano Ronaldo (Portugal) vs Luxembourg
Considering that he has the most hat-tricks in football history, it isn't surprising to see Cristiano Ronaldo on the list. The Manchester United forward netted thrice in his side's 5-0 demolition of Luxembourg in October.
It was his 10th hat-trick for Portugal, which is also the highest by a player on the international stage. However, his exploits were ultimately fruitless, with A Seleção losing to Serbia on the final day.
#3 Memphis Depay (The Netherlands) vs Turkey
The undisputed star of these qualifiers in the UEFA zone, Memphis Depay finished as the joint top-scorer with 12 goals, level with England's Harry Kane after bagging another goal on the final day.
His prolific tally includes four braces, and a hat-trick in the 6-0 rout of Turkey in October. This was the first time the Barcelona striker scored three in international colors, as he capped the year with 17 goals for the Netherlands.
#2 Kylian Mbappe (France) vs Kazakhstan (4)
Only two players scored four goals in World Cup qualifiers in the UEFA zone. The first was Kylian Mbappe, who took Kazakhstan to the cleaners in France's 8-0 rout.
Mbappe scored three times in the first half as the PSG ace broke numerous records on the day, and even became the first French player to score four times in a game in 64 years!
#1 Harry Kane (England) vs Albania, San Marino (4)
Harry Kane's poor form in the Premier League has much-publicised, but he looked perfectly okay in England colors, netting back-to-back hat-tricks in their last two qualifying games.
He scored a perfect hat-trick in the 5-0 demolition of Albania and followed that up with a four-goal salvo against San Marino, equaling a 96-year-old record of scoring consecutive trebles in competitive games.