Three points separate the Jambos from third-placed Celtic, with Rangers just one point off the top.
To add extra intrigue, the title contenders all still have to face off as the Scottish season enters its post-split fixtures this weekend.
After 33 games, the top six and bottom six enter two separate mini-leagues, with each side playing once against the other five sides in their division.
AFP Sport looks at how Hearts shook up the status quo of Scottish football and where the title will be won and lost:
Hearts – 70 pts
The last of Hearts’ four titles came back in 1960, while Aberdeen’s triumph under Alex Ferguson in 1985 was the last time the duopoly of Glasgow giants Celtic and Rangers was broken.
However, the arrival of Brighton owner Tony Bloom as a minority stakeholder has allowed the Edinburgh club to punch above their weight.
Bloom, who made his fortune as a professional gambler, has pioneered the use of data analytics to improve efficiency in player recruitment.
In his first season as Hearts boss, Derek McInnes has blended together some gems picked out by Bloom’s analytics firm Jamestown with a number of key players who were already at the club.
Yet doubts remain over whether, having led for almost the entire season, they can get over the line.
Hearts have failed to win in four consecutive away games and face trips to local rivals Hibernian on Sunday and Celtic on the final day of the season.
But Hearts boast by far the best home record in the league and will hope Tynecastle, where they have not lost this season, plays its part in a potentially decisive clash at home to Rangers on May 4.
Rangers – 69 pts
After a dreadful start that cost Russell Martin his job, Rangers have slowly hunted down Hearts under his successor Danny Rohl.
Martin won just one of his seven league games in charge before being dismissed in October.
Rangers have lost just once in the league since, with a 13-point gap to Hearts reduced to one.
The resurgence under the German was initially built on solid foundations and a string of clean sheets.
But they have clicked offensively in recent weeks, racking up 14 goals in victories over Aberdeen, Dundee United and Falkirk.
The acid test will come in visits to both Hearts and Celtic in a seven-day spell next month.
Rangers are now the bookies’ favourites to win just a second title since the club was liquidated in 2012.
Celtic – 67 pts
Despite a series of self-inflicted wounds in a chaotic campaign on and off the field, Celtic are still in the running for a 14th title in 15 years.
Aged 74, Martin O’Neill has twice answered the rescue call of the Celtic board to take charge after Brendan Rodgers’ departure and Wilfried Nancy’s disastrous reign which lasted only eight games.
A lack of investment in the squad led to Rodgers’ acrimonious exit and has caused an ongoing civil war between the board and the fanbase.
Yet Celtic have consistently ground out results under former boss O’Neill, often digging themselves out of trouble with comebacks and late goals.
The reigning champions have home advantage against both Rangers and Hearts and know that five wins will almost certainly deliver the title to the East End of Glasgow once more.
