They may be less than 40 miles apart at opposite ends of the M23 motorway but the rivalry between Crystal Palace and Brighton has much more to do with history than geography.
"I don't think it was a rivalry between two clubs, I think it was a rivalry between two coaches," says Alan Mullery, who went on to manage both clubs. "Terry Venables was the manager at Crystal Palace. I was the manager of Brighton."
The two of them had been team-mates at Tottenham in the 60s, rivals for the captain's role following the departure of the legendary Dave Mackay.
"We were enemies when he played for Chelsea and I played for Fulham and Tottenham," says Mullery. "He was always trying to compete with me and I was always trying to compete with him."
By the mid-70s they were ambitious young coaches, vying to lead their respective teams to promotion from the old Third Division.
In 1976 they met in the FA Cup first round. Palace scraped through in a second replay after Brighton had a goal disallowed and were made to retake a penalty, which was saved the second time around. Mullery was incensed.
"We edged it and he went into the press room and said: 'They're no good! We were the better side, I wouldn't give you that for them'," Venables recalls. "And he takes a £5 note out of his pocket and throws it on the floor!"
The touch paper had been lit. As the two teams rose through the divisions together their matches against one another drew extraordinary crowds. When Palace fans chanted their support of the 'Eagles' Brighton's responded with 'Seagulls'. It quickly became the new nickname for the south coast club.
In May 1979 both clubs were on the brink of promotion to the First Division. With victory at Newcastle in their final game of the season Brighton achieved it for the first time in their history. Palace had one game still to play. At Selhurst Park 51,000 fans saw them beat Burnley, win promotion and pip Brighton to the Second Division title.
Former Palace defender Jim Cannon recalls finishing above their rivals was an added bonus. "We knew that they were in the air flying to America," he says. "I was told the story that the captain had announced that Palace had won the league and it didn't please Alan Mullery too well!"
"I downed even more champagne to be fair because that browned me off," Mullery admits. "I didn't want to be second - I wanted to be first."
Such was the initial impact Venables and his young team made in the First Division that they were dubbed 'The Team Of The Eighties'. But they could not sustain it. The manager and several key players left and, in 1981, Palace went down. Brighton avoided a similar fate that season; a 3-0 win at Selhurst Park helped them to survive. But Mullery too would soon be moving on.
A year later he took on a surprising new challenge - as the manager of Palace. Given his history with the club, it was an appointment which was unlikely to find favour with many of their fans.
"I wasn't aware of the history, the anti-Brighton, anti-Mullery situation," former chairman Ron Noades would confess some years later. "I brought Mullery in because one of my directors thought he'd be good for us."
Several games between them since have helped to sustain the rivalry. In October 2002 Andy Johnson scored three as Palace won 5-0 in their first league meeting with Brighton in more than a decade. Earlier this season a 3-1 victory for Brighton - who also had Shane Duffy dismissed - was their first top-flight victory in this fixture since the Alan Mullery era.
Neither side can forget that play-off semi-final when Wilfried Zaha blasted Palace a step closer to the Premier League in 2013.
But their most remarkable meeting occurred in another promotion campaign for Palace when a 2-1 home win at Selhurst Park on Easter Monday 1989 only told half the story. It was game in which no fewer than five penalties were awarded. Palace missed three of them!
Mark Bright was initially successful from the spot but saw a second kick saved by the Brighton keeper John Keeley. For their third Ian Wright hit a post.
In the second half, Brighton's Alan Curbishley showed how it should be done. But Palace defender John Pemberton - their third penalty taker that afternoon - clearly had not been paying attention. His effort flew high over the crossbar!