When it comes to collector's items, West Ham United wins at Liverpool are among the rarest of commodities.
As every Hammers fan will no doubt be aware, West Ham have not won at Anfield on any of their previous 41 visits dating back nearly 50 years to a 2-1 victory on 14 September 1963.
The 1963/64 season ended with the Reds being crowned Division One champions and West Ham winning the FA Cup for the first time. Amazingly, Ron Greenwood's side did the 'double' over Bill Shankly's team, scoring a 1-0 success at the Boleyn Ground on 18 January 1964.
One man who played in both victories was full-back Jack Burkett, who recalls West Ham's most-recent yet long-ago win at Anfield clearly.
"I cannot believe I was in the side last time we won there!" half-joked Burkett, who is now 70 and lives in Leigh-on-Sea. "I can certainly remember the game. It was a hard one for us and to win up there against a strong Liverpool team was certainly a feat.
"We had lost twice to late goals at Anfield the previous season, 1-0 in the FA Cup sixth round and 1-0 in the league, which were obviously disappointing results, so to beat them was fantastic.
"Liverpool had some good players back then - players like Roger Hunt, Ian Callaghan and Ian St John - so when you look back, it wasn't a bad result! Martin Peters and Geoff Hurst scored our goals, so we also had some big players on the pitch."
The September 1963 programme cover
While Liverpool were building towards their sixth league title and first since 1947, West Ham were entering a golden period in the club's history. Greenwood's side would add to the FA Cup they lifted in 1964 by winning the European Cup Winners' Cup the following year, while Peters, Hurst and Bobby Moore won the FIFA World Cup alongside Hunt and Callaghan in 1966.
"I think it was a time when we were looking to build a good side," recalls Burkett. "When you look back, games like that were just normal for us, because we won a lot of away games that we weren't expected to win.
"When you win games when people don't give you a chance, like we did at Anfield, it feels even better than when you win a game you're expected to win."
Another man who was part of the West Ham side that day and in their two subsequent cup final successes was goalkeeper Jim Standen, who helped the Hammers to victory by saving Ronnie Moran's second-half penalty.
"Ronnie didn't miss too many penalties but Jim saved his shot that day," said Burkett. "When Jim was on form, he was one of the hardest goalkeepers in the country to beat. He was a real character and very under-rated.
"Ron only paid £6,000 to sign him from Luton Town in 1962 and he turned out to be a real bargain because he was a very good goalkeeper. He was also a very good cricketer, winning a County Championship medal with Worcestershire, and that meant he was very agile."
Fast forward nearly half-a-century and Burkett is looking forward to Sunday's Barclays Premier League fixture at Anfield - although he is unsure whether the present-day Hammers can emulate the feat achieved by Greenwood's side.
"Liverpool are going through a spell of revamping their squad, as they have been for the last few years, but they have been playing well recently. That said, West Ham won last Saturday and that victory should keep them in the Premier League.
"It will be a hard game on Sunday because Liverpool won away at Aston Villa last weekend and Luis Suarez is a striker who is very difficult to keep quiet. If we can do that, I think we can get a draw, which would be as good as a win in my book."