Sports Direct International is set for the FTSE 100 Index for the first time since its stock market debut in 2007 after jumping more than 70% since the start of the year.
But the latest FTSE Group reshuffle will mean a painful exit for security and outsourcing giant Serco, which is on course for relegation to the FTSE 250 Index after seeing its market value hammered by scandals over government contracts.
It saw half a billion pounds wiped from its value in one day last month after the latest revelation that it was facing allegations of fraud over its £ 285 million prisoner escorting service and a freeze on all new government contracts.
This came soon after the electronic tagging scandal erupted in July, in which Serco as well as G4S were accused of overcharging the Government for monitoring offenders.
Serco is one of three blue chip casualties of the quarterly FTSE review, alongside oil and gas services firm John Wood Group and miner Eurasian Natural Resources.
Mr Ashley, who owns around 64% of Sports Direct, has reason to cheer its FTSE 100 success, which comes three years after his Newcastle United football team also secured its top flight promotion, returning to the premier league.
Sports Direct's ascent - which is due to be confirmed by the FTSE Group after market close tomorrow and take place on September 23 - follows impressive trading for the retail group, which has been buoyed by the collapse of rival JJB and a recovering retail sector.
It reported a 40% leap in pre-tax profits to £207.2 million for the year to April 28, while underlying earnings jumped 22.1% higher to £287.9 million.
Shares first floated at 300p when it listed at the end of February 2007, but plunged to just 32p in November the following year in a bumpy start to life as a public company.
The group has risen steadily since then and is now worth more than £7 a share.
Sports Direct updates on trading tomorrow alongside its annual shareholder meeting and is expected to report further sales growth in the first quarter.
But the group's AGM comes as founder Mr Ashley faces flak on two fronts.
Newcastle United fans have been left furious after the Magpies failed to splash any cash in the summer transfer window.
Meanwhile trade unions have raised serious concerns after it emerged that 20,000 part-time staff - some 90% of the workforce - are on zero-hours contracts and cannot be sure how many hours they will work each week.