The Danish playmaker picked up the ball 25 yards out and whistled a low drive past Allan McGregor's despairing dive and into the far corner.
It was our 23rd, final and decisive effort on goal as we dominated the second half following Gaston Ramirez's sending off after an off-the-ball incident with Jan Vertonghen.
Earlier, Harry Kane followed in Eriksen's free-kick with a good reaction finish to cancel out ex-Spur Jake Livermore's first half opener.
Both teams made six changes to their respective line-ups from previous matches. Head Coach Mauricio Pochettino brought in Ben Davies, Mousa Dembele, Federico Fazio, Roberto Soldado and Erik Lamela for the injured Danny Rose, Etienne Capoue, Younes Kaboul, Nacer Chadli and Andros Townsend, while Eric Dier replaced the suspended Kyle Naughton. The home side included former Spurs Michael Dawson, Tom Huddlestone and Livermore.
We fired in the first shot of the contest after five minutes when Soldado tested McGregor but the home keeper saved comfortably. Three minutes later though we were behind as Livermore opened the scoring. Huddlestone’s free-kick was headed clear by Fazio, the ball was returned into the area but cleared once again, this time only as far as our former Academy graduate, who drilled a low 25-yard drive into the bottom corner.
On 15 minutes McGregor was called into action again as Kane hit an angled drive, while the Tigers could easily have added a second shortly after, after creating three chances in quick succession.
Firstly, Hugo Lloris came for a cross but couldn’t collect it cleanly under pressure, the rebound was fired goalwards by Robbie Brady but blocked by Davies. Brady then brought a fantastic one-handed low save down to his left by Lloris, before Nikica Jelavic hit a low cross-shot which was heading for the far corner. Lloris palmed it out but only as far as Hatem Ben Arfa, who could only fire over the bar from 10 yards out in front of goal.
Just before the half hour mark, Dier’s cross was headed clear as far as Eriksen, who hit a right-foot shot which was deflected for a corner and, from the set-piece, Soldado glanced a near-post header wide.
We produced a great move on 38 minutes as Eriksen played a one-two with Dembele and then fed Lamela on the left edge of the area, he let the ball come across him and struck left-footed which McGregor parried away. Ryan Mason clipped over the loose ball but Kane couldn’t get on the end of the centre.
And we finished the half on the offensive, Eriksen fizzing a low inviting ball across the face of the six-yard box but no-one was there to add the finishing touch and we trailed at the interval.
There was a change for the second half with Vlad Chiriches replacing Dier and we had the early impetus with Kane and Eriksen both seeing efforts blocked. And then Hull were reduced to 10 men when Ramirez appeared to kick out at Vertonghen while on the ground and referee Craig Pawson brandished a straight red card.
That certainly saw an increase in possession for us as Hull started to drop deeper and invited us to break them down and we so nearly equalised on 58 minutes when Mason sent in a delightful cross which just evaded Soldado.
And on 61 minutes we did level it up. Livermore brought down Soldado 25 yards from goal and up stepped Eriksen. His curling free-kick hit the post and rebounded straight to Kane who tucked home from 10 yards.
We were well on top now and should have taken the lead five minutes later as Eriksen slipped a pass to Lamela flying down the right wing and his first time cross was flicked inches wide by Soldado. And when Chiriches sent over another centre from the right minutes later, Kane somehow sent his header wide from six yards out.
The pressure was building and Mason brought a smart save out of McGregor with a 30-yard dipping effort, while in the 73rd minute, Eriksen’s fine pass found Lamela cutting in from the left but he drilled well over from the edge of the area.
To their credit, Hull did break forwards when the opportunity presented itself but Jelavic fired well wide on one such occasion from Ahmed Elmohamady’s cross.
Our final change saw Paulinho on for Soldado but the chances were threatening to dry up when Eriksen collected the ball from Aaron Lennon 25 yards out and fired into the corner, sending players and fans alike delirious.
Hull (4-5-1): McGregor, Robertson, Dawson, Davies, Elmohamady, Ramirez, Livermore, Huddlestone (Rosenior 64), Ben Arfa (Meyler 57), Brady (Quinn, 87), Jelavic. Substitutes (not used): Harper, Chester, Hernandez, Sagbo.
Spurs (4-2-3-1): Lloris, Dier (Chiriches 46), Fazio, Vertonghen, Davies, Mason, Dembele (Lennon 59), Eriksen, Kane, Lamela, Soldado (Paulinho 79). Substitutes (not used): Vorm, Ball, Stambouli, Ceballos.
Goals: Hull – Livermore 8; Spurs – Kane 61, Eriksen 90.
Yellow cards: Hull - Livermore, Huddlestone, Quinn. Spurs – Dier.
Red card: Hull – Ramirez.
Referee: Craig Pawson.