The title race in the Championship Division will go into the final round of matches on Saturday.
This after previous table leaders Caribs RFC I went under to Harvard 21-27 to drop to second on the four-team table behind new leaders Trinidad Northers who clobbered Royalians 38-7 at President's Ground, St Ann's.
With the win, Trinidad Northern now leads with 17 points, one more than Caribs RFC whom they meet in the final round while Harvard, third with 14 points entertains winless Royalians as the three teams go into the final week all in with a chance of being declared champions.
Playing at the Queen's Park Savannah I Ground, Caribs had a chance to put a stranglehold on the Championship crown with a victory.
However, Harvard also needed a win to keep their hopes alive and went on the offensive from early on before taking a 5-0 lead when Claudius Butts scored a try in the 17th minute, followed by a conversion miss by Aason Lewis.
Lewis was not enjoying a good start to the counter and also missed a penalty in the 21st before he finally scored on his second attempt in the 31st followed by a second try from Butts and an Antoine Jardine conversion to extend the lead over Caribs to 15-0.
Kalon Alexander finally got Caribs on the scoreboard with a 39th minute try while Reinaldo Bermudez scored the conversion to give their team hope, trailing 7-15 at the half-time whistle.
The second half saw a better start from Carib with Anderson Joseph scoring a try in the 59th minute and Bermudez's conversion to pull their team within a point of their rivals at 14-15.
But Harvard then rediscovered their form of the first-half with Caleb Hector scoring his first try of the match in the 62nd, and Jardien another conversion for a 22-14 lead, quickly followed by a try by team-mate Nigel Ballantyne to extend the advantage to 27-14.
Caribs had one last effort at reeling in Harvard and thanks to a try from Geddes Phillip and Bermudez's third conversion of the afternoon they cut the lead to 21-27.
But in the end, Harvard managed to hang on for the important win to keep their title hopes alive.
When the final round gets going on October 19, Roylians meet Harvard, and Northern plays Caribs.
In the T&TRFU Senior Division, Rainbow, recent winners of the divisional knockout title, ended their Pool B campaign with a perfect 6-0 record and 29 points, nine ahead of Exiles and will meet Pool A winners, Rydeus for the title
In Pool A, Rydeus is in the top spot with a perfect 7-0 record and 33 points, eight ahead of Defence Force (5-2), while Royalians (4-3) is third and only one match left to play.