The National Basketball Association has a new European superstar. Correction – the NBA has a European superstar who's been around seemingly for ever, but who has never managed to deliver when it mattered most. Now, however, Dirk Nowitzki, long the franchise player for the Dallas Mavericks, has delivered – and no longer is he merely the most famous sporting son of the Bavarian city of Würzburg.

On Sunday night Nowitzki led the Mavericks to their first-ever national basketball championship, after a six-game demolition of the supposedly invincible Miami Heat. As a result, he is beyond doubt the most celebrated and most popular European athlete currently plying his trade in North America.

The 2011 NBA finals are likely to be remembered as among the best in decades, a fact reflected in television ratings up 20 per cent on the year before. Part of that arose from the games themselves, almost every one a tight affair in which the lead constantly changed hands, full of late drama.

Then there was the broader storyline, of the underdog veterans from Dallas against basketball's "Hollywood" team of South Beach mercenaries, built around the preening threesome of Dwyane Wade, Chris Bosh and LeBron James – the last-named generally accepted as the game's finest current player, but who earned infamy when he left the Cleveland Cavaliers in a departure he announced live on national television. The Cavaliers branded him a traitor, and so, it seemed, did most Americans. How sweet therefore to see the ungrateful "King James" get his comeuppance.

In fact, what happened was less soap opera than the simple fact that Dallas were simply a better team in every department. And over the series no one contributed more than Nowitzki. He's a 13-season veteran and 10-time All Star about to turn 33, on the old side for a basketball star. Right now, though, he's performing better than ever. If he has a flaw in his game, it is a lack of defence, but lethal shooting skills, combined with exceptional strength on the drive, can make him all but unplayable.

"Dirk Nowitzki is one of the very greatest players in the history of this game," Rick Carlisle said after the Heat had been finally dispatched. As the Mavericks' head coach, Carlisle might be expected to say that. But neutrals are no less impressed. If you want to guard Nowitzki, the former NBA titan-turned-TV commentator Charles Barkley has remarked, "Get a cigarette and a blindfold."

The NBA has had big European stars before: Tony Kukoc, for instance, a member of the all-conquering, Michael Jordan-led Chicago Bulls of the late 1990s, for instance, or Arvydas Sabonis, the great Lithuanian who played for the Portland Trailblazers. But none has been quite the marquee player Nowitzki has been for Dallas. In becoming one, moreover, he had to lay some preconceptions to rest.

European players, it was said, might be talented. But they were unable to handle the grind and physicality of the 82-game, six-month NBA regular season, and the likelihood of 20-plus more games if a championship was to be brought home. The Mavericks' experience in 2006 only seemed to confirm this thesis.

Then as now, Nowitzki and Dallas were facing Miami in the finals. The Mavericks led 2-0, only to collapse and lose the next four games, cementing his reputation as a choker. "Basically, I got hammered the last 13 years," he told reporters before game six, "so hopefully this year I can make the hammering go away."

Mission accomplished. Nowitzki, who was named most valuable player of the 2011 finals, is the first European player to anchor a championship team. By his own exalted standards, Sunday was not one of his greatest nights. For much of the game he seemed tentative. "I couldn't get into a rhythm, but the team carried me," he said afterwards, speaking with the very faintest trace of a German accent.

But this time he delivered when it mattered most. Ten of his 21 points came in the final quarter, as he made five of his last eight shots, compared with just four of his first 19, as the Mavericks completed the decisive 105-95 victory. Throughout the four rounds of play-offs, Nowitzki proved that he now possesses that most priceless gift in sport – the ability to play "in the clutch", to perform in critical situations when the pressure is highest. He also laid to rest suggestions he was a whiner, who complained at injuries that real men would play through without a murmur. James and Wade had staged a bout of fake coughing before the fifth game in Dallas last week, as if to mock Nowitzki who had played the previous evening with a 101 degree fever, and led Dallas to an 86-83 victory nonetheless. "A little childish, a little ignorant," was his comment about the gesture. "I've been in this league for 13 years. I've never faked an injury or illness."

In fact, as a role model it would be hard to beat Dirk Nowitzki. He's always amiable and laid-back, qualities augmented on Sunday by a child's delight in triumph at last. After the final buzzer he walked off the court, wearing a look of disbelief. "This feeling, to be on the best team in the world, is just indescribable, it is amazing," he said at the post-game press conference, his 7ft frame topped off with a "Champions" cap.

Unlike many other superstars, a retinue of minders and handlers does not trail in his wake. Nowitzki has no agent or business manager, is not into product endorsement, and has negotiated his contracts with the Mavericks himself. Maybe he could have made many millions more – but with career earnings approaching $150m (£92m), such considerations are not exactly a life-or-death matter.

But his current prominence has edgier undercurrents too. He's not just a European from southern Germany; he's a white superstar in what is the "blackest" of US major league sports. No less than 82 per cent of NBA players are African-American, compared with 65 per cent in the NFL, 10 per cent in major league baseball, and barely 1 per cent in hockey. Not since Larry Bird, three times an NBA champion and league most valuable player with the Boston Celtics in the 1980s, has a white player been as lionised as Nowitzki.

Inevitably, rarity value alone generates huge coverage, but on occasion also resentment. Black stars have bridled at the frequent implication that a top Caucasian player's success is the result of intelligence and hard work, while for them, an ability at basketball (incidentally President Obama's game of choice) is inborn – in the immortal words of former Detroit Pistons great Isiah Thomas, "like I came dribbling out of my mother's womb".

For now, however, the NBA has more immediate worries. The current players-owners labour contract expires on 30 June, and with the teams losing a combined $300m annually and owners demanding collective player salary cuts of double that, a replacement deal seems far away. And if one is not found, basketball could soon find itself in the same place as the National Football League and be embroiled in a court battle that could endanger the upcoming season.

But that is an issue for late summer and autumn. For the moment, nothing should detract from so memorable a season finale, and the improbable triumph of Dirk Nowitzki and the Dallas Mavericks.

Other white stars

Jerry West

West is remembered for his buzzer-beating 63-foot shot that tied game three of the 1970 NBA Finals against the New York Nicks. Having played 14 years for the LA Lakers, he holds the record for points averaged during a play-off series: 46.3

Rick Barry

One of the greatest pure small forwards of all time thanks to his precise outside shot and execution of team defense principles, along with his unorthodox underhand free throw shooting style. NBA Champion with the 1975 Golden State Warriors.

Peter Maravich

"Pistol" Peter Maravich earned induction into the Basketball Hall of fame following his sudden death at the age of 40. Hailed as one of the great creative, offensive talents, he was a five-time All-Star, playing for the Atlanta Hawks and Boston Celtics.

Larry Bird

Bird played as forward for 13 years at the Boston Celtics, winning three NBA championships, in 1981, 1984 and 1986. He was named MVP in all three years. Bird had a famous but friendly rivalry with Magic Johnson of the Los Angeles Lakers.

Pau Gasol

Gasol, who started at Barcelona, won Rookie of the Year in his first season with the Memphis Grizzlies. In seven years in Memphis Gasol set 12 franchise records, and in 2008 he joined the LA Lakers, where he won the 2008 and 2009 championships.