Despite Emanuele Giaccherini giving the Black Cats the lead after three minutes, it was the Saints who dominated the encounter until the closing stages of the match.
With two minutes of normal time remaining in the clash, Fonte stepped up to keep Southampton's unbeaten run intact, while Sunderland have their first point of the campaign.
Here, Sports Mole dissects the 90 minutes of action that unfolded during the Premier League encounter.
On target: 6
On target: 3
Was the result fair?
Southampton would have felt rightfully aggrieved if they had come away from this afternoon's clash with nothing to show for it. The home side found their stride easily at their home ground, and despite losing an early goal, they were able to regain composure and dominate the fixture. Sunderland manager Paolo Di Canio would have been frustrated to lose all three points in the late manner that they did, but the side did not provide enough quality to kill off the game and grab a second goal.
As mentioned above, they were the better side on the day, using their home advantage from the starting whistle. If it was not for a number of players missing that clinical finish in the final third, you would argue that the Saints would have won the game quite comfortably. Despite being 1-0 down from the third minute, they showed that determination until the end, and it paid off with Fonte's equaliser.
Like Fulham against Sunderland last week, the Black Cats took the lead against the run of play. While they were able to weather the storm until the 88th minute, forward Jozy Altidore was left isolated up front due to Sunderland's need to prevent Southampton's waves of attack. While the North East side looked threatening on the counter, in the final third they struggled to create passages of play to get bodies towards goal.
Sports Mole's man of the match
Victor Wanyama: This may not be an obvious choice, but Wanyama is proving to be a clever swoop by Southampton manager Mauricio Pochettino. He comfortably controlled the middle of the park, allowing his teammates to push forward and preventing Sunderland from grabbing possession. He may not have been involved in the goal-worthy chances, but he was quiet and did an important job to keep his side on top.
This would have to go to Southampton's Jay Rodriguez. While the attacking player had numerous chances, he was unable to make any count. However, one particular opportunity should have seen his side level with around 20 minutes left to play. The 24-year-old found himself in a good position, just a yard or so in front of the Sunderland keeper. The ball flew towards him and should have found the back of the net with ease, but his headed effort fell straight into the hands of Keiren Westwood.
Lee Mason had a lot to contend with from the starting whistle of this game. A quick and fiery start was always going to require the referee to make some decisions. Southampton had two penalty shouts rightfully denied, but the match official made a blunder when he failed to penalise Craig Gardner for a blatant foul on Gaston Ramirez. The Sunderland midfielder was already on a yellow card, so could have easily been sent packing.
Southampton: The Saints travel to Carrow Road to take on Norwich City next Saturday.
Sunderland: The Black Cats head to Selhurst Park for a clash against new boys Crystal Palace.