The world champion's first win at Silverstone, one of his Anglo-French team's home races, was his fifth in eight races and third in a row.
The 24-year-old Spaniard's lead over Ferrari's [ Images ] Michael Schumacher [ Images ], the seven-times champion who finished second ahead of McLaren's [ Images ] Kimi Raikkonen [ Images ], increased to 23 points with 10 races remaining.
Alonso has 74 points from a possible 80, with Schumacher on 51 and Raikkonen on 33.
Worryingly for Schumacher, the chances of Alonso's lead narrowing significantly any time soon looked remote after another untroubled Sunday stroll in the sunshine for the youngest of champions.
The Spaniard took the chequered flag a comfortable 13.9 seconds clear with all but the top nine lapped.
Alonso's triumph was his 14th successive appearance on the podium and, when he has not won this season, he has finished second.
Team mate Giancarlo Fisichella [ Images ] finished fourth, increasing Renault's lead over Ferrari in the constructors' championship.
Alonso, on pole position for the fourth race in a row, led the field through the first corner and controlled the race through to the chequered flag.
Raikkonen and Schumacher followed closely to the first pitstop when they lost ground and the 37-year-old German then got ahead of the Finn after the second stop for tyres and fuel.
Schumacher's brother Ralf had less to smile about, his race over before he had even completed a lap.
Toro Rosso's American rookie Scott Speed nudged Ralf's slow-starting Toyota [ Images ] and the German then steered across the track, hitting Australian Mark Webber's [ Images ] Williams broadside and shunting both out of the race.
Stewards said they would investigate the incident.
Briton Jenson Button's [ Images ] miserable home weekend fizzled out after 10 laps when he pulled over as flames flared from his car's Honda engine.
The only Englishman in the race had lined up a dismal 19th of 22 starters after what he bluntly described as a qualifying 'balls-up' on Saturday.
"It's massively disappointing. It was going well, the car was feeling good," said Button. "We deserved a lot more. It's not all bad luck, though. We need to improve in certain areas."
"I braked going into the corner, saw lots of smoke in the mirrors and that was it," he added."
Toyota's Italian Jarno Trulli [ Images ] also had an afternoon to forget, finishing 11th and still searching for his first point of the season.