Newcastle were outplayed at White Hart Lane and now face a dreadful start to 2006 after it emerged Owen had broken a fifth metatarsal in his foot.
Despite having a few extra days rest to prepare for the game, Newcastle failed to trouble Paul Robinson in the Tottenham goal and never looked like taking anything from the game.
Tainio scored his first goal for Tottenham on the stroke of half-time before Mido wrapped up the points with a fortunate second midway through the second half to leave Magpies manager Graeme Souness facing all kinds of problems as he returns to the north-east.
Newcastle could have opened the scoring after just two minutes when Scott Parker broke into the penalty box but fired the ball past the post.
The home supporters thought the deadlock has been broken on eight minutes when Robbie Keane slotted the ball past Shay Given into the corner of the net. But Keane was adjudged to be offside and referee Howard Webb ruled out the effort, much to the disgust of Spurs' stand-in skipper.
Newcastle defender Peter Ramage was lucky to stay on the pitch after 11 minutes after he made a lunging challenge on Tainio. The young defender escaped with just a caution.
Tottenham went close again on 33 minutes when Michael Carrick played a superb ball into the path of Tainio.
The Finnish midfielder burst into the penalty box but struck a dipping left-foot shot inches past the post.
Keane saw his second effort of the game ruled out for offside on 39 minutes and must have wondered if it was going to be his day.
But the Republic of Ireland international was given something to shout about on the stroke of half-time when Tottenham finally opened the scoring.
Robinson's clearance was flicked on by Mido into the path of Tainio who made no mistake striking a sweet left-foot shot past the stranded Given into the corner of the net for his first goal for the club.
Souness made a double substitution at half-time in an attempt to turn things around. Albert Luque replaced the injured Owen while Celestine Babayaro was brought on for Ramage.
But it was former Newcastle star Jermaine Jenas who had a golden chance to increase Tottenham's lead on 50 minutes.
Keane's sublime pass picked out Jenas who raced into the box, but could only drag his shot into the side-netting.
Tottenham could have been made to pay on the hour mark when Parker unleashed a blistering 35-yard drive on the hour mark which flew inches past the post.
But Mido ensured it was going to be a happy New Year celebration for the Tottenham players when he scored a lucky second on 67 minutes.
Keane's cross picked out his strike partner who hit the ball into the ground and it bounced over Given into the corner of the net.
Newcastle's misery was compounded on 84 minutes when Charles N'Zogbia's shot was only parried by Robinson but Shola Ameobi somehow managed to fire the rebound over the bar.