Both players struggled to find form at Alexandra Palace in London, with Soutar missing 11 darts in the first set as de Sousa took the early lead.

Soutar then took charge as he won the next two sets for the loss of just one leg to go 2-1 up.

De Sousa then retook the lead at 3-2 but missed chances to close the contest out in set six, squandering a match dart at double top.

Soutar levelled the contest at 3-3 when he hit double six at the eighth time of asking, before completing victory in the fourth leg of the deciding set with a 136 checkout.

The contest ended 4-3 to Soutar, and he described the match as "nerve-wracking" but said he was "absolutely buzzing" to get over the line despite not being at his best.

The afternoon session’s second match saw England’s Callan Rydz spring a surprise against compatriot Nathan Aspinall, as he defeated the tenth seed 4-0.

Rydz dropped just four legs throughout the whole contest, ending with a match average of 98.35 and seven 180s.

The victory means Rydz continues his record of winning without dropping a set in the tournament.

England’s Dave Chisnall became the latest player forced to withdraw from the tournament today, after he tested positive for coronavirus.

As a result of Chisnall’s positive test, compatriot and 19^th seed Luke Humphries receives a bye through to round four.

The third round concluded in the evening session with double world champion Gary Anderson of Scotland coming back from the brink to defeat England's Ian White 4-3.

White opened up a 3-0 lead which he clinched when taking out 124 in the decisive leg of the third set.

Anderson won six of the next seven legs to keep himself in the contest, before White missed a match dart in set six.

Anderson forced the decider and landed double ten to seal victory by three legs to one in the final set.

That match was followed by the start of the fourth round and the drama continued, with Michael Smith of England beating Welshman Jonny Clayton in another contest that went the distance.

Clayton won the opening set on a deciding leg before doubling his advantage to two sets to zero.

Smith responded and levelled the contest when he won set four on a 13-darter in a decisive leg, before striking the front again after winning set five.

Clayton took the sixth set on double 12 to send the contest the distance, and although he was at one point in the final set only a leg away from victory, Smith held his nerve to complete checkouts of 72, 65 and 68 to earn the win by six legs to four.

In the night's other match defending champion Gerwyn Price of Wales continued his title defence in style against the Netherlands Dirk van Duijvenbode.

Price lost the first set 3-1 but then reeled off 12 straight legs, earning victory thanks to a match-winning check-out of 136.