Mark Webber wins British Grand Prix
Sahara Force India failed to finish among the points in their home race.
Webber, who took the second win of the season after victory in Monaco, made the most of his superior track grip on harder tires to bravely take Alonso around the outside before nipping back across to defend the lead.
"It was a very interesting race. At the start Fernando had a lot of pace. We had a better strategy in the end there," said Webber, who also won in Silverstone in 2010, from the podium.
"It's a very special victory for the team. ... I'm very proud today."
The second place was enough for Alonso to keep his lead on 129 points in the driver's championship, though the Australian cut it to just 13 with the victory.
"I'm still there. It's the main target for us," said Alonso, the two-time champion, who won last year's race and also in 2006.
"It was quite close today but at the end Mark was much quicker than us. I congratulate him."