Last night's Keane and Vieira: The Best of the Enemies documentary was a great trip down memory lane to the high point of the Premier League's greatest personal rivalry.

But what was most fascinating was the respect and mutual admiration that both players had and still have for each other.

Indeed some of the footage of the infamous tunnel bust up at Highbury in 2005, showed the two sharing a furtive glances and smiles. That was more telling than the verbals as it demonstrated how much they relished testing themselves against each other.

Keane and Vieira may not be friends in the conventional sense but they genuinely seemed to enjoy each other's company during the documentary.

The sporting rivalries with that underlying respect often turn out to be the most satisfying to watch. 

Larry Bird v Magic Johnson

Symbols of the ultra-successful Boston Celtics and Los Angeles Lakers' teams of the 1980s, Bird and Johnson's rivalry pre-dated the NBA, having started in the college ranks.

The duo were constantly compared and pitted against each other as both led their teams to titles. Johnson was seen as the flair player, while Bird was the blue collar man with grit.

Both admitted that they disliked each other in their early years at Lakers and Celtics and used to keep an eye on each other's performances in order to better themselves.

But Bird and Johnson would become close friends at the height of their rivalry after filming this 1985 commerical for Converse...

Following the shoot, Bird invited Johnson to his mother's house where they bonded over dinner and learned that they had much in common in terms of their similar upbringings in poor households. 

They began hoping for each other's success and have remained friends to this day, 30 years on from their heyday.

Indeed when Johnson was diagnosed with HIV in 1991, he felt the need to call Bird in person:

"We were always thinking about each other — what we were doing and how we were doing. I knew that he would want to know and also know from me. And I'm glad I was able to talk to Larry and let him know that I'm gonna be OK, and I knew he was going to be supporting me."

Bird described Johnson's phonecall as "one of the worst feelings you could ever imagine."

Daley Thompson v Jurgen Hingsen

The 1980s saw another epic rivalry that would also end in friendship. 

Britain's Daley Thompson and giant West German Jurgen Hingsen exchanged world records throughout that decade when they reigned supreme in the decathlon.

Like Bird and Johnson, they were very different characters and initially despised each other, especially as their rivalry heated up.

It came to a head when Thompson beat world champion and record holder Hingsen to the gold medal in an epic duel at the 1984 Olympics.

But the respect the two have maintained for over the past three decades is clear.

During London 2012, when Hingsen met Thompson, he told the Daily Mail: "I am always happy when I am in Daley’s company because there is something that connects us. It’s something I want to cherish for the rest of my life. We don’t see each other very often. It is sometimes two or three years. When I turned 50, four years ago, I wanted to invite Daley. There is nobody in the world that would give me more joy and fun than Daley."

Roger Federer v Rafael Nadal

The duel between Roger Federer and Rafael Nadal is probably the greatest sporting rivalry of the past ten years.

But one of the best aspects is the respect and absence of animosity between the pair, despite years pushing each other to ever greater heights.

This blooper reel from a joint-charity effort encapsulates the friendly nature of one of sports' most gripping rivalries...

Ayrton Senna v Alain Prost

One could argue that the multiple Formula 1 champions brought out the worst in each other during acrimonious title battles in the late 80s and early 90s.

But by the end, both men's respect for each other appeared to grow.

Prost was a pallbearer at Senna's funeral after the Brazilian's tragic death in 1994, stating that "a part of himself had died also."

Prior to his death, Senna had also privately acknowledged that battling Prost had actually benefited his career by adding extra motivation.

And at Prost's final Grand Prix in 1993, Senna made a point of pulling Prost onto the top step of the podium is a mark of respect and just days before his death, Senna had this poignant message for his former rival while doing a test lap...