While the London-focused chain offered shares at an initial price of 230p, rampant investor appetite sent the stock soaring 37p or 16% from the offer price to close at 267p.
The wider London market paused for breath - closing down 29 points at 6596.4 - after a frenetic week which saw blue-chip shares propelled higher by the US Federal Reserve's shock decision to maintain the size of its massive economic stimulus drive.
Attention has now shifted to prospects for the wider American economy, whose still-fragile health was behind the decision.The flat mood in London was echoed by another downbeat opening for Wall Street, where the Dow Jones Industrial Average looked set to record another day of falls after hitting a record high in the immediate wake of the Fed's decision. The Dax in Frankfurt edged down slightly and Cac 40 in Paris closed broadly flat.
Sterling was little changed on the money markets, with a pound worth $1.60 and €1.18.
Joe Rundle, head of trading at ETX Capital, said Foxton's initial public offering was a "stunning debut" spurred by high demand from investors bullish about the strength of the UK housing recovery, amid low interest rates and government initiatives to boost the market.
Executive directors and other staff from the chain were sharing in a windfall from a sell-off of a chunk of the business which had been expected to raise £390 million.
It was the latest chunk of shares to whet investor appetites on the London market, after part-nationalised Royal Bank of Scotland capitalised on recent equity market strength to raise £630m by selling another slice of its holding in insurer Direct Line.
Investors are also digesting Barclays' £5.8 billion rights issue, while the Government sold a £3.2bn portion of Lloyds Banking Group earlier this week.
But the move, which cut RBS's stake in the insurer to less than 30%, failed to boost the bank's shares, which fell 4.6p to 364.4p. Direct Line shares slipped 8p to 210p.
In the second tier, estate agent Countrywide benefited from the Foxtons cheer. The group, which rejoined the stock market in March, rose more than 2% or 12p to 570p.
Jardine Lloyd Thompson (JLT) was near the top of the FTSE 250 Index after it announced it was buying the world's fourth largest reinsurance brokerage business for $250m (£156m) in what was hailed as a major coup.
The biggest risers on the FTSE 100 were Shire up 51p to 2593p, Persimmon up 16p to 1127p, GKN 5p ahead to 360.7p and Sainsbury's 5.4p higher to 396.4p.
The biggest fallers on the FTSE 100 were Vedanta Resources 51p lower to 1116p, Antofagasta 34.5p down to 851.5p, Randgold Resources 165p weaker to 4676p and Fresnillo off 36p to 1033p.