The two sets of supporters have their say on the Icelandic midfielder's showing in Wednesday night's Premier League clash at White Hart Lane.
Nacer Chadli gave Tottenham the lead after just seven minutes, before the two sides were given a scare when Swansea striker Bafetimbi Gomis needed several minutes of treatment on the pitch after collapsing.
Manager Garry Monk revealed at the final whistle that the Frenchman was “fine”, however, and the visitors equalised soon after play restarted when a Sigurdsson free-kick came back off the post for Ki Sung-Yeung to slip the ball through the legs of Hugo Lloris.
Ryan Mason's first league goal restored Spurs' lead six minutes into the second-half, with Andros Townsend doubling their advantage nine minutes later, before Sigurdsson volleyed in his seventh strike of the season - which he refused to celebrate against his old side - one minute from the end of normal time to set up a tense finish.
Having shown clear promise during his two-season spell at Tottenham, scoring 13 goals in 83 games, a fair number of fans were disappointed to see the Icelandic midfielder leave the club in the summer deal for Ben Davies, and his form at the Liberty Stadium since has proven that they had good reason to be.
With the likes of Christian Eriksen and Erik Lamela around in north London, the move was likely a necessary one on Spurs' part but, judging from the Twitter reaction to Wednesday’s game, Swansea fans certainly feel like they’ve got the better end of the deal.
Gylfi Sigurdssons technical game is superb. Personally think he is a classy player.— Tomo (@tommlindley) March 4, 2015
It was great of Gylfi Sigurdsson to not celebrate when scoring against @SpursOfficial today, real class shown there.— ReDub- (@ImReDub) March 5, 2015
Gylfi Sigurdsson is basically Christian Eriksen— POLLOS (@TomAFC14) March 4, 2015
Had money on Gylfi to score. Always happens.— Dean (@HelloThisIsDean) March 4, 2015
I know it's easy to say but there was no profit in selling Gylfi and I don't mean financially Pochettino could have used him I reckon #COYS— paul cawthra (@1972pic) March 4, 2015
Does Gylfi Sigurdsson score simple and unexceptional goals??— Dark Snow (@stanis_) March 4, 2015
Thank God for Gylfi!— Katie Biddle (@codekiki) March 4, 2015
Gylfi was such a good signing— Ieuañ (@IeuanCleghorn) March 4, 2015
Was always going to be a tough game but we came through it very well. Good to see Sigurdsson on the WHL pitch again as well. :-D #THFC— Crísandro (@Crisandro_) March 4, 2015
Knew he'd score! Love Gylfi— Seb (@sebhall70) March 4, 2015
My boy gylfi— Gee (@georgieewatts) March 4, 2015