The Blues went ahead after three minutes in the Division Two fixture.
Tony Barton’s corner was headed goalwards by Harry Harris and City’s young centre-half, Alf Wood, steered the ball into his own net.
Pompey increased their lead after 35 minutes when ex-City winger John McClelland centred and Ron Saunders flashed a brilliant header past keeper Harry Dowd.
In the second half another Saunders header thumped against the woodwork, and but for the brilliance of Dowd the visitors would have won by a much bigger margin.
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Pompey reserves started their season by edging a nine-goal thriller, after trailing 2-0 to Swindon Town, before a Fratton Park crowd of 1,709.
With 10 minutes to go and with the score at 4-4, Keith Blackburn notched the winner for the Blues, who lined up as follows: John Milkins, Roy Lunniss, Alfie Noakes, Bobby Campbell, Vince Radcliffe, Brian Lewis, Mickey Lill, Roy Summersby, Keith East, Keith Allen, Keith Blackburn.
Pompey ‘A’ beat Cowes 2-1 in the Hampshire League, with the goals coming from Chris Harding and Barry Figgins.
Meanwhile, Pompey Juniors went down 4-2 against Crystal Palace.
Elsewhere, Everton began their defence of the league championship title by beating Fulham 3-0 at Goodison Park.
Ray Crawford scored a brace as Ipswich Town beat Burnley 3-1 at Portman Road.
Johnny Giles and Albert Quixall both handed in transfer requests after being dropped by Manchester United for their opening game away to Sheffield Wednesday that ended in a 3-3 draw.
George Kirby scored four goals in Southampton’s 6-1 victory over Charlton Athletic at The Dell.
Ron Farmer hit a hat-trick, including two penalties, in Coventry City’s 5-1 win against Crystal Place in a Division Three clash at Highfield Road.
Also in the third division, Bournemouth drew 1-1 away to Southend United.
In Division Four, Aldershot won 4-1 at home to Hartlepool, with Alan Woan grabbing a hat-trick, while Brighton suffered a 2-1 defeat by Workington at The Goldstone Ground.
Pompey manager George Smith looked upon the coming season as one of stabilizing.
He also intended to press on with his plan to deploy the same routine for Saturday mornings at home as those spent before away matches.
The players would meet at a Southsea hotel, go for a stroll, return to the hotel for a light meal and team talk, and finally make their way to Fratton Park.
- ROGER HOLMES