Tonga tackled themselves to a standstill in the second half preventing Wales from adding a single point after centres Owen Williams and Ashley Beck scored first half tries and Leigh Halfpenny added the remainder with his boot.
Tonga replied through winger Will Helu who scored a well taken try with fly half Latiume Fosita knocking over the conversion.
Wales dominated the second half but couldn’t find a way through the stubborn Sea Eagles defence. Hallam Amos and George North were both denied tries by the TMO in the second spell while Luke Charteris also had the ball knocked from his grasp in the process of scoring to ensure a scoreless second half.
The first half proved a stop-start affair but that could have had something to do with the fact Wales started the match with 11 changes from the side which defeated Argentina while Tonga began with four alterations after their loss to France.
Despite dominating possession Wales were left frustrated by Tonga who managed to disrupt the Welsh flow with a string of last ditch tackles and pugnacious defence.
Wales dominated the early exchanges and camped inside the Tongan half but it took 13 minutes before Ryan Jones’ side broke the deadlock with an easy Halfpenny penalty.
Owen Williams then used a combination of strength and pace to bump of would be tacklers and the cover defence as he weaved his way over from halfway. As usual, Halfpenny banged over the conversion to put Wales 17-0 ahead.
The game was 20 minutes old before Tonga had a brief spell with the ball with huge centre Hemani Paea making his presence felt but Ken Owens and Ian Evans doubled up to deny the Sea Eagles.
Wing Will Helu then gifted Wales back possession twice in quick succession due to poor handling skills which ensured the Sea Eagles continued to struggle to get a foothold in the game. His generosity proved costly as North went on a shuddering run to eventually set up Beck who plonked the ball down in the corner despite Vaea Taione’s best attempt close to the touchline. Halfpenny slotted the conversion from wide out to put Wales 17-0 up.
Helu then made amends for his earlier mishaps when he sliced back against the grain to score by the posts. With fly half Fosita adding the conversion, Tonga had pegged back the score to 17-7.
The second half followed a similar path as the first with Wales finding Tonga a tough nut to crack. Amos appeared to have scored on his debut but Siale Piutau did enough to drag his left foot into touch to deny the young winger.
Sione Kalamafoni left the field against his wishes after taking an almighty bang to the head when making a tackle to signal a raft of changes for the Sea Eagles.
Charteris stormed over from a close range lineout but Tukulua Lokotui’s hand dislodged the ball as the second row was in the process of diving over to frustrate the home side further.
Wales had a second try disallowed after Charteris was adjudged to have been offside when North powered his way over from close range.
Wales’ heavy artillery of Alun Wyn Jones and Ryan Jones peppered the Tongan line in the dying stages but the Sea Eagles held firm bravely.
The defeat condemned Tonga to their fourth consecutive loss away from home – the last time they lost four consecutive away matches was between 2007 and 2009, part of a five-game losing streak on the road while Wales will head into next week’s fourth and final clash of the autumn against Australia with momentum on their side, having added Tonga to the scalp of Argentina.
