Terriers coach Carlos Corberan is an advocate of teams playing through the Covid-19 outbreak when they can for the sake of their fans' mental health but for long periods it seemed to be doing Huddersfield supporters more harm than good until Thomas turned it into a very happy Christmas for them.
Blackpool were leading 2-1 and had wasted a couple of good chances to add to it when Jordan Gabriel launched into a brainless tackle to pick up his second yellow card of a match which seemed to be draining confidence out of the hosts until that pumped their belief right back up.
With half-an-hour to play, Huddersfield sensed their opportunity, piled on attacking substitutes and parked their concerns about Lees to claim a dramatic victory thanks to the Wales international whose fading form has been almost as much of a talking point as the quality of his early-season football was. Both were fine finishes.
The game started the way Boxing Day games used to in the era when defending was banned on December 26 only with far mroe intensity. It was fun to watch.
Huddersfield responded quickly, Danny Ward producing an excellent near-post header from Harry Toffolo's equally good cross only a couple of minutes later.
At that point with both teams getting the ball down and Huddersfield pressing ferociously, it looked set up for a really good game between two teams who know their formations well - Huddersfield's 3-4-2-1 and Blackpool a ver clear 4-4-2, albeit with Keshi Anderson given plenty of licence to wander from the left wing.
A good cushioned header from Thomas found Duane Holmes who tried to return it without realising Thomas had not continued his run. As more incidents like that happened, the Terriers seem to lose a bit of confidence.
Making it worse was when Anderson chipped in a cross and former Sheffield United and Wednesday striker Gary Madine climbed over Matty Pearson to bundle a header in.
When Lewis O'Brien dragged a shot just wide, Ward was fractionally away from getting a touch as he slid in, but Holmes's shot midway through the first half was more typical of how
Huddersfield's performance was going, picked out by Danel Sinani but only able to produce a touch which bobbled the ball up for an even less controlled shot.
They were fortunate not to go further behind, Anderson putting a good header wide from Yates's delivery, then Jordan Gabriel missing an equally good chance.
The second opportunity went begging as Huddersfield centre-back Lees was spark out in Blackpool's half having been caught by Madine's right elbow, then a stray left arm. He was down for around eight minutes before being carefully stretchered off to be replaced by concussion substitute Ollie Turton.
One of Turton's first acts as the Blackpool fans booed their former player was to release Holmes down the left but neither Sinani nor Scott High could put the ball in.
Lee Nicholls made an unconvincing palmed save late in the half,wrong-footed by the curl on Sonny Carey's shot.
Huddersfield came out more revved up for the second half, Toffolo producing an admittedly not all that dangerous header from a corner and High showing a hunger to defend by throwing his way in front of a Carey shot.
Toffolo was finding plenty of space on the left, but Ward frustratingly stepped over his low curling cross in the 58th minute.
Then came the turning point. Booked for a foul in the tenth added minute of the first half, Gabriel brainlessly clattered into O'Brien on the touchline and there seemed little doubt what the outcome would be.
Corberan pounced. Jordan Rhodes has not long come on as a second centre-forward but with 10 minutes to go the 3-5-2 became an out-and-out 3-4-3, Rhodes and Josh Koroma flanking Ward as Aaron Rowe came on at wing-back and Toffolo dropping into the back three.
The magic, though, came from elsewhere, Thomas coming inside, exchanging passes with Rhodes and producing a good finish to equalise almost as soon as Rowe and Koroma were on the field.
The John Smith's Stadium went nuts but Thomas was not finished yet, getting himself over the bouncing ball as Blackpool failed to get a corner away and smashing it into the net in the 84th minute.
Huddersfield Town: Nicholls; Pearson, Lees (Turton 41), Sarr (Rowe 80); Thomas, O'Brien, High (Rhodes 59), Toffolo; Holmes (Koroma 80), Sinani; Ward.
Unused substitutes: Ruffels, Schofield, Russell.
Blackpool: Grimshaw; Lawrence-Gabriel, Ekpiteta, Gretarsson, Husband; Bowler (Sterling 65), Dougall, Carey (Mitchell 82), Anderson; Yates (Keogh 65), Madine (Lavery 75).
Unused substitutes: Moore, Hamilton, John-Jules.
Referee: J Simpson (Lancashire).