With his side mere moments away from securing a hard-fought point against the English Premier League giants, rotten luck struck the Aussie defender in the 89th minute.
Spurs need to beat Inter at home and will nearly certainly need something to show from their trip to Barca on match day six to qualify for the knockout stage.
Jurgen Klopp's side stay second in Group C after Napoli and Paris Saint-Germain played out a 1-1 draw in Naples to leave the entire group separated by only two points going into the final two matchdays.
'We can beat them.
Pochettino insists it will not be embarrassing if Tottenham are knocked out.
There were large swathes of empty seats around Wembley as Tottenham fans showed their frustration at their team's spluttering European form.
PSV, which stayed on one point and can not now qualify for the knockout stage, had defended stoutly after going ahead through Luuk De Jong's header from Gaston Pereiro's corner.More news: Accused Mexican drug lord 'El Chapo' faces U.S. trial
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"Today [his job] was to play alone like a holding midfielder, with Christian [Eriksen] and Dele Alli next to him". Toby Alderweireld starts alongside Davinson Sanchez in the middle of defence while Ben Davies continues at left-back. Who else but Harry Kane! .
Lucas Moura was the notable exception.
Kane was to the fore once again in the dying embers of the contest, his headed attempted clipping Sainsbury on its way into the net to leave PSV on the brink of elimination.
Alli lost another duel with Zoet soon after, this time watching in despair as the Dutch keeper pushed away his low drive.
Pochettino withdrew Lucas for Erik Lamela in the 62nd minute and the Spurs crowd widely jeered the decision, but the manager played it down after the match.
But Tottenham kept pressing in composed style and Kane drilled a fierce strike that Zoet repelled at his near post.
There was some conjecture about whether it should be ruled an own goal, however, match officials awarded the goal to Kane. Paulo Gazzaniga is set to deputize in goal. It was a vital contribution from Gazzaniga as Kane poached Tottenham's 89th-minute victor, rising to head home via a deflection off Sainsbury.