There are hat-tricks and then there are 'perfect' hat-tricks.

For those unfamiliar, it's when a football player scores three goals in one game: one using their left foot, another using their right foot and finally a header.

It's topic that was brought into the spotlight by Christian Pulisic this week who, after achieving the feat during the win at Burnley, became only the 31st Premier League player to do so.

And that made us wonder: how many 'perfect' hat-tricks have the greatest two goal-scorers of this generation - Cristiano Ronaldo and Lionel Messi - scored thus far?

Well, sorry Messi fans, but the answer is a big fat zero for the latter and his slower rate of headed goals has been the main problem for him with both Barcelona and Argentina.

Ronaldo's 'perfect' hat-tricks

But what about his eternal rival? Ronaldo has fared much better and according to Transfermarkt, has scored no less than eight over the years: seven with Real Madrid and one for Portugal.

Ronaldo is widely regarded as the best all-round footballer in the modern game, so perhaps it's no surprise that he's scored so many all-round hat-tricks.

And bearing that in mind, it only made sense to reminisce on those eight moments of perfection from Ronaldo, so check them all out down below:

Vs Villarreal 2010/11

Yes, that's right, there were no 'perfect' hat-tricks in Ronaldo's early days at Manchester United, but he opened the floodgates for perfection with a treble against the Yellow Submarines in 2011.

He arrived at the back post to tap in an opener with his right foot, headed home a second in front of the goalkeeper and closed proceedings with a left-footed strike on the swivel.

Vs Getafe 2010/11

And after going nearly a decade without a 'perfect' treble, Ronaldo bagged his second just four months after the first with a masterclass against Getafe.

Ronaldo first found the net with a typically gravity-defying header, doubled the advantage with a left-footed effort into an undefended goal and killed off the game with a Panenka penalty.

Vs Getafe 2012/13

Poor Getafe, they've been on the end of two 'perfect' Ronaldo hat-tricks and just two seasons apart.

Mesut Ozil turned provider for the opening strike as Ronaldo found the bottom corner with his left foot, before converting an acrobatic back-post header and another spot kick.

Vs Espanyol 2014/15

The first 'perfect' hat-trick to take place away from home, Ronaldo exorcised the demons of Real's Champions League exit to Juventus with a stellar performance at Espanyol.

The Portuguese first defied the goalkeeper with a stinging left-footed shot and then a placed effort on his stronger side; eventually nodding home a third at the back post.

Vs Espanyol 2015/16

Having scored four goals during the reverse fixture earlier in the season, albeit not perfectly, Ronaldo once again made Espanyol his play thing with a Bernabeu treble.

During a 6-0 annihilation, Espanyol were left helpless as Ronaldo converted an early penalty, scored a weak-footed worldie with two Ronaldo chops and then casually headed home a third.

Vs Andorra 2016

Ronaldo might have scored plenty of hat-tricks on the international stage, but his treble as part of four goals against Andorra remains his only 'perfect' trio for Portugal.

A delicious left-footed volley got the rout underway, a header into the ground made it two and a rifled right-footed strike ensured Andorra were on the end of perfection.

Vs Bayern Munich 2016/17

There's scoring a 'perfect' hat-trick and then there's scoring a 'perfect' hat-trick in a Champions League quarter-final. This might just be Ronaldo's goal-scoring magnum opus.

None other than a prime Manuel Neuer was on the end of a brave headed finish, a calculated left-footed volley and a simple tap-in off Ronaldo's stronger boot.

Vs Real Sociedad 2017/18

The hat-tricks were certainly drying up for Ronaldo by this point in his Real career, but there was still time for one more dose of perfection at the Bernabeu.

He ticked off his stronger foot by converting a cross from Marcelo, headed home a second just a few minutes later and then used his weaker side to profit from a goalkeeping error.