Sales at Sotheby's, Christie's and Phillips generated a combined £280.5m (including premium), the highest total for a summer Contemporary series in this category in the capital.
The highest estimated work of the series however, Francis Bacon's Study for a Pope I, attracted no bids against a £25m-35m pitch at Sotheby's Contemporary art evening sale on July 1, while an Andy Warhol silkscreen estimated at £12m-18m also failed to find a buyer at the same event.
The hammer total of £112.9m was below predictions of £142.2m-202.6m.
The sale itself took place as a protest was held outside the auction house with around 100 people demonstrating over wages and sick pay for cleaners employed by the company's contractors. On the hottest day of the year so far in London, clients had to walk past the protest to enter the premises.
Inside the air-conditioned saleroom, the take-up was still pretty strong with 49 of the 58 lots selling overall (85%).
Warhol's One Dollar Bill (Silver Certificate) from 1962 led the sale at £18.5m. Four bidders chased tit - the artist's first hand-painted dollar picture. It was pitched at £13m-18m.
Despite the failure of Study for a Pope I, which lacked the intensity of other works from the artist's series, Sotheby's sold two Bacon self-portraits - a single canvas from 1975 which sold for £13.5m to a private collector and a triptych entitled Three Studies for Self-Portrait from 1980 took £13m from a different bidder on the phone.
Works by Bacon also made a key contribution to the series total with Christie's sale the night before led by Study for Head of Isabel Rawsthorne and George Dyer, a diptych from 1967 which was estimated at £8m-12m and sold at £10.8m.
Another Bacon that drew bidding was the rare landscape Two Men Working in a Field from 1971, which was knocked down at £9.5m against a £7m-10m estimate. Christie's sale posted a total of £82.4m against a pre-sale estimate of £82.3m-117.1m.
Best of British
Drawing fervent competition, Lucian Freud's Four Eggs on a Plate from 2002 easily exceeded its £100,000-150,000 estimate at Sotheby's.
A small picture measuring just 4 x 6in (10 x 15cm), it was given by the artist to his close friend the late Dowager Duchess of Devonshire, and came to auction from her estate. "Good old Lu. I take him eggs every time I go to London," 'Debo' once recalled.
The bidding opened at £80,000 but with numerous parties vying for the picture, it rose quickly to a multi-estimate sum and was eventually knocked down to a commission bidder at £820,000.
Other than Bacon and Freud, British artists making high prices across the sales included:
• Chris Ofili, The Holy Virgin Mary - £2.5m at Christie's (auction record).
• David Hockney, Arranged Felled Trees - £2.9m at Sotheby's.
• Frank Auerbach, Head of Gerda Boehm - £1.85m at Sotheby's (auction record for work on paper).
• Paula Rego, The cadet and his Sister - £950,000 at Sotheby's (auction record).