The most remarkable title win in English football history and perhaps all of European football is within touching distance for Leicester City.
Superlatives have long since run out for Claudio Ranieri's Premier League leaders, with the Foxes (21-9-3) just three wins from securing a first top-flight title in the club's history, having been marooned at the bottom of the Premier League in April of last season.
West Ham United's visit to King Power Stadium on Sunday is the first of five history-defining games for Ranieri's side.
The Foxes (21-9-3) cannot be caught at the top of the table if they win three of their remaining matches. And the runaway leaders are able to go 10 points clear at the summit if they beat the Hammers - with closest title challengers Tottenham Hotspur not playing until Monday evening.
However, Ranieri insists he is only focusing on Leicester.
"I don't want to make a comparison between another team, or my team against another team," said Ranieri. "I'm watching just my team.
"I want my team to have a strong character, not only when everything is right, but also when it goes badly. It's important because it's life and life is not always the same sunshine. Sometimes there is a bad forecast and you have to stay together and fight together."
Leicester's surge of five wins on the trot has been on the strength of an air-tight defence that carries a club-record 490-minute shutout streak since Craig Gardner scored in the 50th minute for West Bromwich Albion in a 2-2 draw March 1.
However, there's also plenty for Sunday's visitors West Ham (13-13-6) to play for. The Hammers are five points outside the Champions League qualifying places with six games remaining, and will be keen to make amends for Wednesday's 2-1 FA Cup quarterfinal ouster at the hands of Manchester United.
"It was a huge disappointment because we wanted to go to Wembley and then go on and win the Cup," said West Ham manager Slaven Bilic. "But we want to finish high and we are motivated to do that in our final six games, starting at Leicester on Sunday.
"We need points to finish high in the table. Do we need to win on Sunday to qualify for the Champions League? Well, we know we need points if we are to finish high."
Leicester have posted seven clean sheets in their last eight matches at King Power Stadium and have given up just five goals during a 12-match unbeaten run (8-4-0) there since a 5-2 defeat to Arsenal on Sept. 26.
"It's hard to play them because obviously they are winning games 1-0 or whatever," Bilic remarked. "They are very patient and their transition is unbelievable, offensively or defensively.
"They are playing simple football, but they have players who are capable of counter-attacking, beating three or four players in a tight space, and they are great on set-pieces. They are very hard to beat."
Leicester may be a daunting opponent, but an upset is not out of the question. The Hammers' form on the road has been a big factor in helping them to a position to scrap for Champions League qualification, with Bilic's side losing just four of their last 16 league away games.
However, in-form striker Andy Carroll - coming off a hat trick in West Ham's 3-3 draw versus Arsenal last weekend - has found the back of the net just twice in the past two seasons away from home.
The centre-forward is likely to lead the line on Sunday, with fellow striker Diafra Sakho out with a knee injury. Full-back Carl Jenkinson is a long-term absentee for the Hammers.
Leicester have no reported injury concerns as they head into the most important month in the club's history.
The Foxes have made a habit of disregarding past form this season, but West Ham have won 10 of 17 total top-flight meetings between these clubs. First-half goals by Shinji Okazaki and Riyad Mahrez were enough for a 2-1 victory in the reverse fixture Aug. 15, with Dimitri Payet netting for West Ham just before the hour mark.