Liverpool's manager, Gerard Houllier, fielded three of his new signings, the goalkeeper, Sander Westerveld, central defender Sami Hyypia and striker Titi Camara in his club's opening domestic warm-up fixture.
Fowler, who sat out the final six league games of last season because of two suspensions, was set up by Patrik Berger to open the scoring in the 26th minute with a low drive into the bottom corner from 20 yards. Fowler was followed on to the scoresheet 10 minutes from time by Riedle after a run and cross by David Thompson.
Aston Villa's chairman Doug Ellis, manager John Gregory and assistant manager Steve Harrison had to wait 63 minutes to see their next transfer target, Robbie Keane, who came on and looked sharp as Wolves staged a spirited recovery.
Liverpool's neighbours, Everton, won 3-2 at Chester, where Nick Barmby scored twice as the Premiership side came from a goal down to win. Barmby curled in his first goal after 79 minutes and, after Darren Wright stabbed in an equaliser, he wrapped up the victory with a superb 30-yard right- foot drive in the 85th minute. Ironically, Barmby had missed the best two chances of a goalless first 45 minutes.
A Newcastle United side lacking Alan Shearer, who has an ankle injury, and Duncan Ferguson, who is having treatment for a groin problem, lost 2-1 away to Livingston.
Goalkeeper Ian McCaldon kept Livingston in the match, while Newcastle's keeper, Lionel Perez, miscued a clearance in the first half, to give David Bingham the chance to score the first goal from 25 yards.
The former Celtic striker Simon Donnelly netted the winner as Sheffield Wednesday scored twice in the last four minutes to beat First Division QPR 2-1 in a pre-season friendly at Loftus Road.