London: Lewis Hamilton is enjoying the intensity of his Formula One rivalry with Ferrari's Sebastian Vettel, even if the Mercedes driver recognises that the smiles could suddenly turn sour.
The two men, with seven world championships between them, fought a wheel-to-wheel duel in Spain on Sunday with Hamilton emerging the winner and now six points behind the German.
Each has two wins this year from five races.
"What I love about the race with Sebastian is... I love tennis, I love watching (Roger) Federer and (Novak) Djokovic in a final, and what I really admire is the consistency," Hamilton said afterwards.
"Every hit of that ball, just one misplaced or (in) the net can mean the whole game. So I admire their concentration and how they are so awesome and stay at the limit. I felt today I had that battle."
Hamilton, a triple champion, has had a dominant car and his team mate as main rival for the past three years but Nico Rosberg's abrupt retirement after winning the 2016 title has changed that.
He is now up against a quadruple champion, once dominant with Red Bull, who has a machine to match the Mercedes.
Racing against a teammate -- with the constructors' championship always a consideration and the same strategist calling the shots for both -- can never be as no-holds barred.
Last year in Spain, the Mercedes drivers collided at the start -- leaving Hamilton 43 points adrift of Rosberg.
"Having a battle and a fight with another team, it’s so much more enjoyable," said Hamilton, whose new team mate Valtteri Bottas won in Russia last month but retired in Barcelona with an engine failure.
Bottas still played a major part in Hamilton's win, helping to delay Vettel long enough to enable the Briton to recoup vital seconds.
The top two lapped everyone, with the exception of Red Bull's third-placed Australian Daniel Ricciardo, and their mutual respect shone through afterwards with some light banter.
"We just had a very close battle today and if it had gone a different direction, it would have been different between us," said Hamilton, who went wheel-to-wheel with the German after Vettel's final pitstop and sounded breathless at times.
Hamilton was forced aside, and protested angrily over the radio about the move being 'dangerous', but there was no contact made and he was able to take the lead later.
"You know how racing goes. If he had hit me in Turn One and I didn't finish and he won the race, it would not have been 'great job, Sebastian'," said Hamilton.