The ?26million record signing scored the winning goal from the penalty spot for the second week running.
Tottenham dominated the game, but a killer instinct was lacking at times and Michel Vorm also pulled off a couple of top saves in the Swansea goal.
That killer instinct, of course, would probably have been there had Gareth Bale been here, but the star forward was sunning himself in Marbella instead.
Without him, Tottenham were impressive, but only in patches.
Soldado took his spot-kick well while a pair of bruising performances from Etienne Capoue and Paulinho stifled Swansea's creativity.
Tottenham should have had the chance to bury the game in the first half but referee Neil Swarbrick failed to give what looked to be a clear penalty following a foul by Jonjo Shelvey on Andros Townsend.
Despite having to go through a 4,500-mile round trip to Georgia in midweek, Spurs pressed from the kick-off.
Swansea had little time on the ball, but the hosts had to resort to long-range shots as Ashley Williams kept Soldado quiet.
Paulinho drove in to Vorm's arms from long range and Capoue did the same from a similar angle.
Source: PA
Source: PA