In the 1990s, there would have been no contest as Sir Alex Ferguson and his star-studded team of world-class players swept all before them domestically as well as winning the Champions League to complete a remarkable treble in 1999.

Back then, Chelsea were regarded as a Cup team rather than a direct title challenger – winning the FA Cup in 1996/97 and League Cup in 1997/98 – but failing to mount a sustained assault for the Premier League trophy.

That all changed when Roman Abramovich swaggered into English football in 2003 and invested heavily to transform the club into a major Premier League force.

Since that watershed moment, both clubs have lifted the Premier League title five times apiece to establish themselves as the leading clubs in England and consequently often find themselves competing against one another for players.

It seems that every summer at least one player is linked with both clubs, but who has been the more successful in landing their dual targets?

Arjen Robben

Joined: Chelsea

From: PSV

Less than a year after Abramovich had completed his takeover and already the Blues seemed close to usurping United as the most desirable Premier League club for players to join.

In March 2004, Chelsea announced the signing of Arjen Robben from PSV Eindhoven for a £12m fee with the flying Dutchman agreeing to join up with the club for the next season.

Chelsea’s signing of the 20-year-old would have been a bitter pill to swallow for those at Old Trafford as it was reported by the BBC that extensive talks between the club and Robben had taken place and that he had been given a tour of Old Trafford.

Jon Obi Mikel

Joined: Chelsea

From: Lyn Oslo

If Arjen Robben’s decision to choose Chelsea over Manchester United would have disappointed Sir Alex Ferguson, the Scot would’ve been positively fuming after missing out on John Obi Mikel a couple of years later.

Following a hugely promising start to his career, Manchester United swooped to sign Mikel in 2005, paying Lyn Oslo a fee of £4m and parading him in a United shirt in a press conference.

However, Chelsea claimed that it was they who had signed him instead after he had impressed Jose Mourinho during trial training sessions in West London.

Eventually, a year after being pictured in a United shirt, Mikel ended up in England, instead wearing the blue colours of Chelsea after they shelled out £12m to their league rivals in compensation.

Eden Hazard

Joined: Chelsea

From: Lille

Fresh from winning his second consecutive Ligue 1 Player of the Year award in 2012 at the age of 21, Eden Hazard was a man in demand with all of Europe’s top clubs weighing up a bid for the Lille winger.

Following huge speculation surrounding his future, Hazard eventually confirmed that he had opted to join Chelsea in June, just a few weeks after the club had improbably won their maiden Champions League trophy.

After agreeing to join the Blues in a £32m deal, Hazard said: “When they won the Champions League I told myself, ‘Why not Chelsea?”

“There was a struggle between Chelsea and [Manchester] United but, for me, Chelsea has the best project. It’s a wonderful club.”

Since moving to Chelsea in 2012, Hazard has lifted two Premier League titles, the League Cup and the Europa League, while United have also won four major honours.

Anthony Martial

Joined: Manchester United

From: Monaco

Manchester United stunned world football when they splashed out an initial £36m (potentially rising to £58m depending on clauses) to sign a little-known French teenager named Anthony Martial from Monaco on deadline day in 2015.

Martial made an explosive start to life at Old Trafford by scoring a mesmerising solo goal on debut against Liverpool before establishing himself as a key player for Louis van Gaal.

It emerged shortly after, as reported by the Evening Standard, that Martial had started to find his feet that Chelsea had made a late attempt to lure him to Stamford Bridge instead but that he had chosen United instead.

Pedro

Joined: Chelsea

From: Barcelona

A matter of days before United secured the services of Martial, they missed out on Pedro as the Spanish winger signed for Chelsea in a deal worth £21.4m from Barcelona.

According to reports, just two days before Pedro was presented to the media as a Chelsea player, he had agreed personal terms to join United with only the transfer fee still left to sort.

In a summer that saw United miss out on a variety of high-profile targets including Real Madrid’s Sergio Ramos and Bayern Munich’s Thomas Muller, the failure to get the Pedro deal over the line was seen as another failure on Ed Woodward’s part.

Romelu Lukaku

Joined: Manchester United

From: Everton

Despite top-scoring for Chelsea as they won the Premier League title, Diego Costa’s future at the club appeared to be bleak after he had his turned in January by the riches on offer in the Chinese Super League.

Antonio Conte reportedly told Costa that he would not be relying on him for the upcoming campaign and switched his attentions to landing Romelu Lukaku to spearhead a new-look attack.

Embarrassingly for Chelsea, though, they were unable to bring the towering Belgian forward back to the Bridge for a second spell as he instead opted to link up with Jose Mourinho at Old Trafford instead.

Lukaku sealed a £75m move to United from Everton in July leaving Chelsea scrambling around for a Costa replacement with Alvaro Morata, formerly linked with the Red Devils, reportedly their new first-choice target.

Transfer tussles fought: Six

Chelsea signings: Four

Man Utd signings: Two