Lorenzo enjoys 'one giant leap' at Estoril.

Dressed as an astronaut, Jorge Lorenzo made 'one giant leap' into Valentino Rossi's MotoGP World Championship lead with victory at Estoril on Sunday.

Lorenzo dominated the Portuguese Grand Prix for all but the first few turns to claim his fourth win of the season by a commanding 6.3sec and first win from pole since his debut MotoGP victory at Estoril in 2008.

"It's been perfect weekend for us. I dominated practice and felt great on the bike. It is not always like this so we have to enjoy it," smiled Lorenzo.

"In two or three corners I overtook Dani [Pedrosa] and opened a little one-second gap. At first it was difficult to increase that gap, but as the tyres went down I could keep my pace.

"But I didn't expect this victory with such a big gap and I didn't expect Rossi to finish fourth," he admitted.

After qualifying a close second on the grid, Rossi was pushed back to fourth by the end of the opening lap - where he remained to the chequered flag.

The reigning six time MotoGP champion finished a massive 23.4sec behind his Fiat Yamaha team-mate and saw his title advantage cut from 30 to 18 points.

While the Italian struggled, a returning Casey Stoner claimed an excellent second position for Ducati, with Pedrosa over 13 seconds ahead of Rossi in third for Honda.

"Today Dani and Casey helped me to reduce the gap to Valentino, but it could happen the opposite way in the future - they might be ahead of me," warned Lorenzo.

Rossi's world championship lead has now dropped to less than one race win (25 points) for the first time since the German Grand Prix on July 19, with three rounds and 75 points remaining. Rossi and Lorenzo are now officially the only riders that can win the 2009 championship.

"I think Valentino is the rider who has to win the championship," reflected Lorenzo. "So he has the pressure to win it. I still don't have anything to lose. The championship is less impossible, but it continues to be difficult because beating Valentino in the last races is not easy."

However, Lorenzo believes he is in excellent shape.

"It is not only Estoril. We are going fast at almost every race now," he said. "Valentino was so good last time at Misano and we could only finish second, but here I was faster."

Even team manager Daniele Romagnoli was surprised by his rider's Estoril dominance.

"We were confident today that we had a strong chance for a good race, but we didn't expect such domination," said Romagnoli. "Now the championship is even more interesting and the last few races will bring great attention on us all, but we're looking forward to the challenge!"

Lorenzo celebrated his victory with a mock moon-walk before planting his Lorenzo's Land flag into the gravel.

Lorenzo came up with the astronaut theme when he found out that Yamaha would be running a special silver-and-white livery to promote Fiat's latest Punto - the 23-year-old turning it into a spacesuit with a special helmet design.

"I liked my leathers and helmet a lot this weekend and I wanted to celebrate like Neil Armstong, because it is 40 years after they first walked on the moon," explained Jorge.

Lorenzo's victory also handed Yamaha the 2009 Constructors' title, while Fiat Yamaha clinched the Teams' Championship on Sunday.

"Yamaha is my brand and I'm so happy that they could celebrate," said Lorenzo.

The Australian Grand Prix at Phillip Island takes place on October 18.