The 28-year-old Briton started from pole position, but having lost the lead on the opening lap, she recovered to pass Fabienne Wohlwend (Bunker Racing) in the closing stages and take her second victory of the season after winning the opening round in Austria last month. Alice finished two seconds clear of Fabienne as defending champion Jamie Chadwick (Veloce Racing) completed the podium.
Emma Kimiläinen (Ecurie W), Nerea Marti (W Series Academy Team) and Beitske Visser (M. Forbes Motorsport) were fourth, fifth and sixth respectively. British quartet Sarah Moore (Scuderia W), debutant Abbi Pulling (PUMA W Series Team), Abbie Eaton (Ecurie W) and Jessica Hawkins (Racing X) completed the top 10, meaning all six British drivers scored points in their home race.
With five of this season's eight rounds remaining – round four is at Hungary's Hungaroring on 31 July – Alice leads Jamie by six points. Sarah is a further 12 points back in third and Fabienne is fourth on 34 points after scoring her best-ever W Series finish and her second podium of the season.
More than 100,000 fans flocked to Silverstone on another glorious day on Formula 1's British Grand Prix weekend, and close racing throughout the W Series field kept them on the edges of their seats.
Fabienne made a fast start from second on the grid and went wheel-to-wheel with pole-sitter Alice before taking the lead at Village. Beitske – who had an engine change before the race – was slow away from the second row and dropped to seventh at the end of lap one, promoting Emma, Nerea and Sarah by one place each.
Fabienne and Alice traded fastest laps to pull three seconds clear of Jamie in third with 20 minutes left, and the leading pair were separated by just six tenths of a second at the halfway stage. Further back, Abbie overtook Belen Garcia (Scuderia W) for ninth on the inside at Vale after a prolonged wheel-to-wheel battle.
Having stalled on the grid, Miki Koyama (Sirin Racing) stopped at Village to bring out the safety car with 11 minutes remaining. There were less than eight minutes left on the clock when the safety car period ended, and Alice regained the lead three minutes later when Fabienne ran wide at Club allowing Alice through on the inside.
Alice dipped a wheel into the gravel at Luffield to keep Fabienne in contention, but Alice held on to make it back-to-back victories on home soil having won the last W Series race to be contested in Britain at Brands Hatch in August 2019.
Sarah and Beitske went side-by-side for several corners and Beitske eventually came out on top to take sixth with less than a minute to go. That put Sarah under pressure from Abbi but Sarah held on, while behind them Belen and Jessica made contact on the final lap.
Alice Powell, 28, UK, Racing X, said:
"It's an amazing feeling to win on home soil. I've experienced lots of British Grand Prix weekends but never from this side and I want to thank every single fan out there for the amazing support. To race and win in front of this crowd is the stuff that dreams are made of and it was extra special to have my family here to see it. It wasn't the best of starts for me, I got a bad launch and was behind Fabienne [Wohlwend]. But I knew I had the pace and was faster, and luckily she made an error which let me sneak through and I managed to bring it home from there."