The England midfielder showed great composure to fire past Mark Howard in the 74th minute to finally pierce the Blades’ defensive resistance, the spot-kick awarded for handball from Jay McEveley.
It wasn’t a game laden with goalscoring opportunities, with the visitors defending in numbers to restrict our chances, while we weren’t seriously troubled on the counter-attack – so the goal was a crucial one on the night. How important it will be overall, we will find out in next week’s return.
Head Coach Mauricio Pochettino recalled Emmanuel Adebayor to the starting XI, while Ryan Mason returned from injury to take his place in midfield.
As you’d expect for a semi-final, the atmosphere crackled at kick-off and there was a vibrant start to the game - mostly, it has to be said, from the visitors. They hustled and harried and looked to put their mark on the game early on, although chances were few and far between for both sides.
In fact it was 13 minutes before any real goalmouth action and that came from the Blades. Jamie Murphy turned on halfway and threaded a pass to Marc McNulty, who ran at our defence but was crowded out and his attempted shot cannoned away to safety.
We were neat and tidy in possession up until the final third but were finding it difficult to find gaps in United’s compact backline, while they were happy to hit us on the break at every opportunity and went close on one such occasion on 22 minutes.
McNulty laid the ball out wide right to Jamal Campbell-Ryce, he advanced towards the edge of the area and fizzed a low teasing cross which evaded everyone and just missed the far post.
Two minutes later we tested United’s goalkeeper Howard for the first time when Townsend was upended 25 yards out on the right flank. He took the free-kick and curled the set-piece which Eric Dier met well, but it was too close to Howard and he was able to palm away for a corner.
With the short pass game failing to penetrate United, we went for the longer option on 35 minutes when Christian Eriksen delivered a delightful ball over the top which Adebayor brought down well with one touch but then could only fire his shot over the bar under pressure from McEveley.
The visitors grew into the game as the half went on and it needed a fine Dier tackle to prevent Murphy breaking through just inside the area, while Stefan Scougall cut in from the right five minutes before the break but fired wide.
Then in stoppage time we were awarded another free-kick in a similar position to before and the same combination went close again, Dier getting on the end of Townsend’s delivery but this time just glancing his header past the post and we went in goalless at the break.
The second period began the same as the first, with plenty of endeavour but few noteworthy opportunities. We certainly dominated possession in the opening 15 minutes and forced a succession of corners, but didn’t test Howard in the United goal.
We made a double change just after the hour mark with Roberto Soldado and Mousa Dembele replacing Adebayor and Mason respectively and the Spaniard was swiftly in the action, laying a pass in to Townsend but his shot was deflected away for a corner, which came to nothing.
Then came the breakthrough. We were patient in possession, switching the ball from left to right and back again looking for the opening. Vertonghen picked up the ball and strode forward, shaped to shoot but clipped a lovely pass over the top which Soldado stuck out a leg to control and as the ball bounced up, McEveley clearly handled and referee Neil Swarbrick pointed to the spot. Up stepped Townsend to coolly fire past Howard and set us on our way on the night.
McEveley looked to make amends at the other end but could only head well over the crossbar from Bob Harris’ free-kick 40 yards out, Vertonghen needed to be in the right place to cut out Campbell-Ryce’s cross on a counter-attack and substitute Jose Baxter couldn’t get on the end of a deep cross as the Blades searched for a late equaliser.
And when Murphy curled a right-footed effort wide in injury time, that was the final chance of the match and we reconvene in Sheffield in a week’s time with a one-goal lead.
Spurs (4-2-3-1): Vorm, Walker, Vertonghen, Dier, Davies, Mason (Dembele 64), Stambouli (Paulinho 75), Townsend, Eriksen, Kane, Adebayor (Soldado 64). Substitutes (not used): Friedel, Rose, Kaboul, Lennon.
United (4-1-4-1): Howard, Flynn, McEveley, Basham, Harris, Doyle, Campbell-Ryce, Scougall (Wallace 87) Reed, Murphy, McNulty (Baxter 83). Substitutes (not used): Turner, Alcock, Higdon, Kennedy, Adams.
Goals: Spurs – Townsend (penalty) 74.
Yellows: Spurs – Adebayor, Sheff Utd - McEveley.
Referee: Neil Swarbrick.