Harry Kane No. 1 in his position - Tottenham boss Mauricio Pochettino

LONDON -- Mauricio Pochettino hailed record-breaker Harry Kane as one of the best in the world and said hard work is the secret to the striker's success after Tottenham's 5-2 win over Southampton.

Kane scored a second hat trick in three days following his treble at Burnley to break Alan Shearer's 22-year-old record for Premier League goals in a calendar year and surpass Lionel Messi as the top scorer for club and country in 2017 among players in elite European leagues.

Kane finished this year on 56 goals for club and country, of which 39 have come in the Premier League.

"For me, he's world class," Pochettino said. "I think today, [number] one striker in the world, specific position. Who's better than him?

"I think he's one of the best because it's difficult to say he's the best but today he showed to everyone that he's one of the best."

He added: "When you are at this level, you need to fight with all your determination to keep at this level.

"To do this, you need to work hard, more than before, be more professional and more focused. If you achieve something and you say, 'I need to run 10 metres but I will run only nine,' you will cheat yourself, and that is a massive problem.

"The most important thing is to keep the same mentality. The secret is to work hard every day. You cannot say no for one day. That is the secret of the big players like Harry, Cristiano Ronaldo, Messi and company. You cannot afford not to work every day."

Either Messi or Ronaldo finished as the top scorer in Europe's top five leagues every year from 2010 to 2016 and the Spurs manager added: "Both [Harry's] achievements are massive.

"To break the Premier League record set by Alan Shearer and then if you see the last seven or eight or nine years always Messi and Cristiano and today it's Harry Kane, a player from Tottenham, a massive achievement and we feel it's our achievement, something we share with his teammates and the club.

"And to score these goals at 24. He is not only a massive talent, how he is as a person and a professional it's amazing to work with him."

Kane had scored three league goals and was a relative unknown when Pochettino was appointed Spurs manager in May 2014 but he has now scored 96 in the top flight and one more will take him level with Teddy Sheringham as the club's all-time leading Premier League scorer.

"It's an amazing story for us, as a coaching staff, when you look at him play -- not only feel happy [but] so proud of all this he has achieved," said Pochettino, who added that Tuesday match was so open it could have finished 7-4 to Spurs.

"It's double happiness because he's a player you trust and after all that he is today, he deserves because he is professional and takes care of himself and he scores goals."

But Pochettino said he has come to expect such performances from his striker, adding to Sky Sports: "It doesn't surprise us because every day we see how he works, his determination, how professional he is, and that can only be good for him. He's a very talented player. He's a great professional and a good example for everybody, not just his goals."

Reflecting on the calendar year, Pochettino added: "We are so ambitious, but I am so happy. We have finished this year in a very good way, and I hope next year we can win more."