Second-half goals from Moses Simon and Efe Ambrose finally broke Swaziland's resistance and sent Nigeria through to the final group stage of the CAF section of World Cup qualifying with a 2-0 win.
Sunday Oliseh's team were held to a goalless draw in Friday's opening leg and they endured a similar story of first-half frustration in front of their own fans at Port Harcourt.
The unexpectedly dogged defence of a team ranked 130th in the world by FIFA was eventually broken six minutes after half-time when Simon curled home a magnificent 35-yard free-kick.
Nigeria had to wait until the 87th minute to make certain of their progress as Ambrose converted another set-play from close range, before Phumlani Dlamini's second yellow card meant the visitors concluded their unlikely World Cup bid with 10 men.
Swaziland spent the majority of the first leg on the back foot and, despite pre-match suggestions from their coach Harris Bulunga that they would take a more attacking approach, a familiar pattern developed during the opening stages at the Adokie Amiesiemaka Stadium.
Odion Ighalo sent a header narrowly over the crossbar and the Watford striker was at the forefront of an expansive start from Oliseh's men.
Simon scuffed Ahmed Musa's cross into the arms of Swaziland goalkeeper Nhlanhla Gwebu, before Ighalo swivelled to shoot agonisingly wide after half an hour.
Against the run of play, Swaziland almost took a sensational lead - Nigeria keeper Carl Ikeme misjudging his attempt to claim a cross, only for Sandile Dlamini to miss with the goal at his mercy.
After the break, Nigeria's Sylvester Igboun was guilty of similar profligacy following excellent work down the flank from Ighalo and it was left to Simon to calm the nerves of the home supporters with his superb opener.
Ighalo's luckless outing in front of goal continued when he collected a throughball from substitute Obafemi Martins and drew a sharp low save from Gwenbu.
Nigeria were forced to play the final 10 minutes without goal hero Simon, who suffered an apparent hamstring injury, but Ambrose ensured they finished with a flourish as the defender volleyed home.
Phumlani Dlamini concluded his own contribution in more inauspicious circumstances, collecting bookings for two lunging tackles in the space of six minutes either side of Ambrose's crucial goal.