Harry Kane has last-gasp goal ruled out as qualification goes to wire for Spurs

Spurs, who had laboured against their Portuguese opponents, thought they had won it - and booked their place in the knockout stages - with the last kick of the game as Harry Kane swept home from close range, but after a lengthy check the England captain was ruled offside and it ended 1-1.

For a long time it looked like Spurs were going to lose as former striker Marcus Edwards, who joined them as an eight-year-old, put Sporting on course for a famous win with his first-half goal.

Rodrigo Bentancur levelled in the 80th minute before the late drama, which saw Tottenham boss Antonio Conte sent off when Kane's effort was ruled out.

Victory would have assured Spurs of their place in the last 16, but now next week's trip to Marseille is full of jeopardy, though a draw will be enough to send Conte's men through and a win would seal their position as Group D winners.

That will not be an easy task considering their abject first-half performance here and the fact they have a poor record away from home in Europe over the last few seasons.

Spurs not only had qualification on their agenda, they were also looking to respond to successive Premier League defeats, but endured a tough start.

Sporting, who won the reverse fixture 2-0 in the second round of matches, fired two warning shots inside the opening 20 minutes as Sebastian Coates put a free header from a corner wide before Paulinho flashed an effort just over after a fine cross from Pedro Porro.

The visitors took a deserved lead in the 22nd minute and there was no surprise who scored it.

Edwards, who left Spurs in 2019 after failing to build on that initial promise, silenced the home crowd when he drilled in from 25 yards, though questions will be asked about Cristian Romero, who backed off and allowed the shot, and goalkeeper Hugo Lloris, who looked to be beaten too easily.

The rest of the first half was not much better and Sporting had the ball in the back of the net again four minutes before the break, but Coates deliberately handled from a corner and was booked.

It was not difficult for Conte's side to improve after the break and they laid siege on the Sporting goal in the opening 10 minutes of the second half.

They had three efforts in quick succession as Antonio Adan saved Eric Dier's volley, Romero had a goal-bound shot blocked and Matt Doherty fired over.

Spurs were breaking the lines in a way they could not in the first half and Son Heung-min again tested Adan with a fierce shot that was parried, while Dier headed onto the roof of the net.

Sporting had two brilliant chances to end the contest but Lloris denied Fatawu Issahaku when he was through on goal and then, after Lloris kept out Porro's effort, Flavio Nazinho embarrassingly missed an open net from the rebound.

His misery was compounded as Spurs finally levelled with 10 minutes remaining.

Adan had been superb with his aerial domination, but he missed an Ivan Perisic corner and Bentancur headed into an open net.

Dier missed a sitter to score as he headed wide from close range and then Bentancur fired over.

But there was to be late drama and Spurs thought they had won it after Kane rammed home from close range when Emerson Royal's header fell into his path.

However, wild scenes of celebration were cut short as VAR ruled there was an offside and ecstasy turned to agony.

Conte lost his cool and was sent off for good measure as Spurs head to France next week with work still to do.