(Reuters) - Argentina must play a flawless game on Sunday if they are to beat a powerful German team and lift the World Cup for the third time, their coach Alejandro Sabella said.

Germany go into the final at Rio de Janeiro's Maracana stadium as favorites after their 7-1 demolition of hosts Brazil in the semi-final, but Argentina have shown a surprising defensive steel and in Lionel Messi they have a match-turner.

"We need to play great, concentrate hard, occupy spaces quickly, not risk the ball where it shouldn't be risked," said Sabella, who has imbued a new work ethic in the Argentine side during their run to a first World Cup final since 1990.

"From the physical, tactical and character points of view, Germany have always been extremely strong," he told reporters on Saturday.

"And now they have an elaborate style of play, with passes between lines, diagonal balls to the forwards. We need a perfect match to beat them."

Seeing their great South American rivals play in the final at the Maracana is torture for Brazilians who had fully expected their own team to be there fighting for the trophy.

The 100,000 or so Argentineans in Rio for the game have been making hay out of that, with songs and jokes mocking Brazil and blue-and-white flags draped all around the famous hilltop Christ statue. But Sabella took a more respectful approach.

"For this to be taking place in a country that has won the most in football is important, it's not a small matter," he said of five-times world champions Brazil.

"I've always been a great respecter and admirer of Brazilian football. So coming to the final in Brazil is something that makes us really proud."

"SELF-MOTIVATIONAL"

Sabella said he had ideas in mind for a team-talk, but stressed that his charges should really need little extra incentive than being in a World Cup final.

"I think this is a match where you almost don't need to say anything because it is self-motivational. But there's always something to look for to bring that added extra," he said.

"We'll give our all as always, with sacrifice, humility, hard work, being down to earth, giving before receiving, protecting one another, so that Argentina can be a champion again. We will do our best. More than that we cannot do."

Argentina had evolved positively since South Africa four years ago, Sabella said, when they crashed out of the quarter-finals 4-0 to Germany in a game that exposed then coach Diego Maradona's tactical naivety and more cavalier approach.

"Our team is more conservative than four years ago, we are looking to triumph via a different path," he said. "The teams are different although most of the players are the same."

Germany, in fact, knocked Argentina out of the last two World Cups, and, as West Germany, beat them in the 1990 final. Argentina's last World Cup trophy was in 1986 when they won the final, also against West Germany.

"It was very painful, we know what happened," said defender Jose Basanta when asked about the 1990 final in Italy.

"We want to write a new story tomorrow. We are very motivated. We've been touched with a magic wand, and we must enjoy the moment. It goes by very fast, so we have to enjoy it. God-willing, everything can be achieved."