Originally known as The Still, the site at Quinnell Court, on Kent Street, has been bought for £751,000.
The property, containing nine flats, was among 112 lots listed across southern England by Clive Emson Auctioneers.
Rob Marchant, the firm’s Hampshire auctioneer, said: ‘We anticipated keen interest, given that the gross rental yield at a purchase price of £751,000 equates to a decent return of just under 6.8 per cent, and this proved to be the case.
‘Inflation is at 7 per cent, and with double-digit figures forecast by the end of the year, savings money is losing value – and property investors with cash are making it work hard for better returns through buying bricks and mortar.’
In total, the flats, which include one-bedroom and studio properties, generates £51,000 in rent a year.
Mr Marchant added: ‘This freehold former public house, which was called the Still, is close to the main campus buildings at the city university and comprises nine self-contained flats – a mix of studio and one-bedroom units.’
Other lots which went under the hammer include two dilapidated garages, in Wordsworth Avenue.
It attracted major interest, with the lot selling for £21,505 after 27 bids.
The auctioneers set a guide price of between £8,000 and £9,000.
Other properties sold include a mid-terrace, two-bedroom house, in Londesborough Road, Southsea.
It was acquired for £198,500 after 41 bids.
The next online auction from Clive Emson is on June 16, with lot entries closing on May 24.