The enigma of Sergio Ramos was encapsulated in Real Madrid's 4-0 away thumping of Bayern Munich in the Champions League last month, writes Richard Fitzpatrick.

His two headed goals from set pieces decided the tie. He was a match-winner with not even 20 minutes registered on the clock.

Yet 15 minutes later, knowing that if he picked up another yellow card in the tournament it would rule him out of the final, he ploughed through Philipp Lahm. It was a mystery he was not booked for the challenge.

It was an extraordinary, though completely in character, moment of recklessness. He has racked up 19 red cards during his career with Real Madrid, more than any other player in the club's history.

He is difficult to fathom. Physically brave; but prone to feigning injury. A natural leader; but capable of idiotic verbal blunders, which have made him a laughing stock in Spain. A couple of summers ago he tweeted excitedly that he was in New York at the Yankee stadium: "What a spectacular city!" Attached was a picture of Las Vegas.

His rise has been meteoric. He was 19 when Real Madrid shelled out a reported fee of €27m to lure him from Sevilla, the team his family supports. He was already capped by Spain. Last year, he became the youngest player to surpass the 100-mark for international caps.

He has been one of the lynchpins of Spain's triple-winning international team over the last six years - as a marauding full-back on the team's right-hand flank in Euro 2008 and the World Cup, and then in the centre alongside Gerard Pique after Carles Puyol's knees caved in.

Ramos entered Euro 2012 bickering with his new partner, a rift that festered during their clubs' ugly rivalry, but the pair united for the greater good.

Ramos also exorcised a ghost in that tournament. Two months earlier, he had ballooned Real's fourth penalty over the bar against Bayern Munich in the Champions League semi-final, and his side tumbled out.

He was lambasted for the miss. That night he told his father and Rene, his brother and agent, that the next penalty he got he would score with a Panenka. "That'll shut them up," he vowed.

Unable to practice the dinked flick of the boot in training in case it were caught on camera, he did so in open play. It worked, his penalty proving crucial in the shoot-out win over Portugal.

During the fractious years of Jose Mourinho's three-year reign at Real Madrid, Ramos was a consistent critic, although he bit his tongue in public. Behind closed doors, however, he spoke candidly to Florentino Perez, the club president, when canvassed about the shortcomings of the Portuguese.

Real Madrid's players used to joke that they could forecast Mourinho's mood based on the front-page covers of AS and Marca, the city's two sports dailies. If a picture of Ramos or Casillas adorned the front, it would be "cold, with rain probable" for the day.

Ramos had a training ground set-to with Mourinho in January 2012. Real Madrid had shipped an embarrassing 3-1 defeat to Pep Guardiola's Barca in the league at Santiago Bernabeu just before Christmas. Another defeat soon followed in the first leg of a Copa del Rey quarter-final.

Mourinho was furious with Ramos because he had not been marking Puyol at a corner, as directed, which led to Barca's captain scoring with a header. He challenged Ramos about his negligence in training two days after the incident.

Ramos countered, saying he was forced to swap marking duties because Pique and Puyol were drawing defenders and creating space. He added witheringly that: "As you have never been a player, you wouldn't know that this is sometimes necessary." A raw nerve with Mourinho had been touched.

There were further scraps. Mourinho dropped Ramos later that year for a Champions League tie with Manchester City at the Bernabeu for insubordination, but Ramos got the last say.

He was one of six players, according to El Pais, who requested a transfer if Mourinho was kept on last summer.

Mourinho left the club soon after, having lost three Champions League semi-finals in a row.

La Decima, Real Madrid's 10th European Cup win, the club's great obsession, was beyond him. The Champions League trophy is the only piece of silverware missing from Ramos's personal trophy cabinet. He could put that right tonight in Lisbon.

If he does, watch him fetch a matador's cape afterwards for a trademark celebration as he apes the toreador's passes.

He is a born killer.

n  Richard Fitzpatrick is the author of El Clasico: Barcelona v Real Madrid: Football's Greatest Rivalry (Bloomsbury)