(CNN) -- Activists protesting against Arctic oil drilling infiltrated a Formula One race in Belgium Sunday, but the off-track incident did not stop Sebastian Vettel's march towards a fourth successive world title.
Two paragliders from the environmental group Greenpeace flew over the circuit at Spa-Francorchamps, displaying a banner criticizing the operations of Belgian Grand Prix sponsor Shell.
Then a second group of men managed to climb the main grandstand overlooking the starting grid and hung down a banner emblazoned "Arctic oil? Shell no!"
They then hung on ropes watching the race, which was effectively decided when Vettel overtook pole-sitter Lewis Hamilton on the first lap and motored clear in his Red Bull to win by almost 17 seconds from Fernando Alonso and extend his championship lead to 46 points.
However, the protests were not over -- the Greenpeace activists managed to unveil another banner above the winner's podium, and triumphantly posted the proof on the international group's Twitter page.
It posted a series of messages Sunday asking followers to demand that Shell backs down in its plans to drill in the Arctic, which it says will increase melting of the ice sheet and destabilize the global climate.
Greenpeace also reported that the grandstand climbers had been arrested.
Shell signed a multi-year sponsorship deal with the Belgian race in 2011, and has been involved in F1 since its inception in 1950 -- working mainly with Ferrari, the most successful team in the elite motorsport.
Its website says the Arctic "holds around 30% of the world's undiscovered natural gas and 13% of its yet-to-find oil. This amounts to around 400 billion barrels of oil equivalent, 10 times the total oil and gas produced to date in the North Sea.
"Developing the Arctic could be essential to securing energy supplies for the future, but it will mean balancing economic, environmental and social challenges."
In July, Greenpeace activists scaled one of Europe's tallest buildings -- London's Shard -- to protest Shell's Arctic drilling. The multinational company's main UK offices are near the Shard.
In February Shell announced it had suspended its Alaskan offshore drilling for the rest of 2013 but planned to resume "in the future." In previous months, two of its drilling vessels were damaged in the area and had to be towed to Asia for repairs.
Meanwhile, Vettel shrugged off the protests to celebrate his fifth victory in 11 races this season, and his second at Spa following his 2011 success.
"It was a fantastic race for us from start to finish," the German told reporters. "It helped on the first lap getting a tow off Lewis through Eau Rouge. Once I passed him we could control the race.
"So a great result, with the car better than we expected going into the race which I really enjoyed a lot.
"Fortunately there was no rain, so no need for any critical calls to be made, and a comfortable afternoon for us."
Vettel's teammate Mark Webber finished fifth, giving Red Bull a 77-point lead in the constructors' standings.
The veteran Australian will leave F1 at the end of this season to drive for Porche in sportscar racing, and he is expected to be replaced by compatriot Daniel Ricciardo from Red Bull's feeder team Toro Rosso.
Vettel appeared to confirm as much, saying: "It would make sense for Ricciardo as he has been at Red Bull for a long time. People will argue that he might not be ready, but was I ready when I joined?"
Alonso moved up to second in the drivers' standings above Lotus' Kimi Raikkonen, who did not finish for the first time in 39 races -- a run stretching back to 2009 when he was still at Ferrari.
The Finn retired due to a brake problem on the 26th lap, ending his record-breaking stretch of earning points in 27 races.
Two-time world champion Alonso was pleased with his efforts after starting from ninth on the grid.
"We had to recover some places because we were not okay yesterday," he said. "We were then okay from the start, but the race was a little boring once we had second place."
Hamilton, who won from pole in Hungary in the last race before the mid-season break in July, had to settle for third place.
"We had a tough race, these guys were faster than us, but I'm happy with the result," the 2008 world champion said.
"When we started we felt we didn't have as good a package as Red Bull and Ferrari. We'll try and do what we can in Monza, but from Singapore I hope we can be strong from there."
His teammate Nico Rosberg was fourth, giving second-placed Mercedes a 17-point advantage over nearest rival Ferrari.
Hamilton's former McLaren teammate Jenson Button was sixth -- the 2009 world champion won the race last year -- and Ferrari's Felipe Massa seventh.
Lotus' Romain Grosjean took eighth and Adrian Sutil was ninth in a consolation for Force India, whose other driver Paul Di Resta had to retire after being hit by Williams' Pastor Maldonado.
Ricciardo completed the top 10, giving the 24-year-old his fourth points-scoring race this season to be 14th overall in the standings.