The former Swansea City target man marked his maiden Premier League start in our colours following his summer move from south Wales with an early breakthrough from Christian Eriksen's free-kick.
It was also the Spaniard's first domestic goal for us and came amid a spell of intense first-half pressure in the driving rain, but it took until the 89th minute for us to find a second through Dele Alli.
We'd dominated the play without really creating any clear chances but when substitute Harry Kane picked out his fellow England international with a delightful cross-field pass, the midfielder pinged into the top corner at the second time of asking after initially being denied by Lukasz Fabianski.