Ba scored a sumptuous curling finish 10 minutes into the second half to register his first goal since February, only for Defoe to level with a quarter of an hour remaining. The visitors were only on terms for four minutes, however, before Ben Arfa put the Magpies back in front from the penalty spot after Rafael van der Vaart had tripped him in the area.
The win gave Newcastle their first victory on the first day of a top-flight campaign in five years, while Tottenham have now lost their last four opening-day fixtures which have been away from home.
Newcastle manager Alan Pardew was able to start with strike duo Papiss Cisse and Ba as well as French midfield pair Yohan Cabaye and Ben Arfa despite all four being injury doubts heading into the game. Fabricio Coloccini was missing through injury, but fellow centre-back Steven Taylor made his first appearance of 2012 after suffering from a long-term injury.
Tottenham head coach Andre Villas-Boas raised eyebrows with his first starting XI by leaving summer signing Jan Vertonghen on the bench, preferring to go with veteran centre-back William Gallas alongside Younes Kaboul. The club's other summer signing, Gylfi Sigurdsson, did start however.
Tottenham finished one place and four points above Newcastle last season, although fourth place was not enough to secure Champions League football for the Londoners. It was Spurs who dictated much of the early tempo as the home side began with plenty of caution.
That is not a quality many would immediately bestow upon Magpies midfielder Cheick Tiote, however, and he drew great cheers from the home support for his typically crunching early tackle on Kyle Walker. It looked as though that challenge had caused the Newcastle man an injury, but the robust Ivorian played through it.
Despite plenty of enterprising play from Spurs, with Aaron Lennon looking particularly dangerous on the counter-attack, it was Newcastle who had the first chance. Papiss Cisse turned and shot from around 20 yards from goal, and his low strike deflected off the boot of strike partner Demba Ba's boot and trickled just wide, much to the relief of the helpless Brad Friedel.
Soon Spurs began to carve out the opportunities that their play warranted. Sigurdsson saw his curling free-kick tipped wide by Tim Krul after Danny Simpson was perhaps fortunate to not receive second yellow card for a foul on Gareth Bale.
Jermain Defoe got the better of Taylor but saw his low strike rebound off the foot of the near post. Bale was also denied by the frame of the goal when his header back across goal from Lennon's cross was over Krul but came back off the crossbar.
Newcastle began to take the game to their visitors after the break, but their opening goal still had the feel of being against the run of play when it came on 54 minutes. Kyle Walker's attempt at a headed clearance saw the ball drop at the feet of Ba, who took a touch before caressing a curling shot out of Friedel's reach and into the net. It was his first goal since he netted on Cisse's debut for the club against Aston Villa on February 5.
Soon afterwards Pardew was sent to the stands by referee Martin Atkinson after he had angrily shoved a linesman.
As the game wore on Spurs struggled to create as much as they had done before the break, and it was a scrappy goal which got them back on terms on 76 minutes. Gallas met Lennon's cross with a header that Krul saved with his legs, and the ball rebounded of the post before Defoe reacted quickest to bundle it home.
Just three-and-a-half minutes later, however, Newcastle were back in front. Ben Arfa's trickery saw him sneak in between Lennon and Van der Vaart and burst into the box, inviting the Dutchman to trip him over. After a discussion with Ba about who should take the spot-kick, Ben Arfa was vindicated in insisting he did by sending Friedel the wrong way.
Clearly deflated by that goal, Spurs were unable to muster much of a late assault on a share of the points, and Pardew saw his team close out the win from on high.