Prayag United erased a goal's deficit to beat Mohun Bagan 2-1 in a second round I-League tie at Kolkata's Salt Lake Stadium on Friday.
Okolie Odafa put Mohun Bagan in the lead early in the first half but the team failed to preserve the advantage conceding two goals thereafter.
Nigerian Ranti Martins and New Zealander Kayne Vincent found the target in tandem for United SC, which effectively defended the lead in a barren second half to ensure full three points from the match.
Having lost its first round 'away' outing 0-2 against Shillong Lajong FC, Mohun Bagan began in the right earnest and pressed for the lead making regular forays into the United SC box.
Odafa made two early attempts just to see the United SC goalkeeper Subrata Paul neutralising them. But the highest paid Nigerian striker persisted with his efforts and succeeded in his third attempt in the 19th minute.
Odafa, got the better of his marker Gourmangi Singh, and covered a few yards before beating the onrushing Paul with a deft placement.
The goal lightened Mohun Bagan's hopes but a defensive error by Khelemba Meetei ended the team's dominance in the 27th minute.
With the United SC left-back Sukhen Dey setting up a cross in the Mohun Bagan box, Metei failed to mark United striker Ranti Martins who appeared to find a touch to send the ball over the approaching Bagan goalkeeper Arindam Bhattacharya.
Encouraged by the equaliser, United SC doubled its attacks and found the lead in the 45th minute.
Then Kayne Vincent, who replaced suspended defender Bello Rasaq as the third foreigner in the team, managed to tip the ball into the over before Arindam could come out to clear.
Mohun Bagan overhauled its midfield in the second half introducing Nigerian Stanley Okoroigwe in the centre.
The player eased Bagan's midfield worries and brought a semblance of stability in the logistic line. Bagan tried hard to find the equaliser after the break but its efforts were not sharp enough to beat Paul in the United goal.
Odafa and Tolgay Ozbey, the two stars in the Mohun Bagan attack - found a chance each in the 75th and 77th minutes but failed to get the ball home.
Tolgay's attempt went wide from close while Odafa saw his placement cleared from the line by Dipak Mondal.
With two wins in its kitty Prayag United joined the leaders with six points while Mohun Bagan remained at the bottom without any points to its credit.