Harry Kane was relieved after helping Spurs come from behind to beat Olympiakos on Tuesday.
The Greek side shocked Spurs when they went 2-0 up in the first-half, only for Delel Alli to bring one back before half-time.
A double from Kane and terrific strike from Serge Aurier sealed the win for Jose Mourinho's side, who are now into the last-16.
Kane told BT Sport: "It was a disappointing start, we know that and did not come out with any energy and they got the two goals and put us under pressure, it was an uphill struggle but we go the goals and it feels good to qualify.
"We needed to be calm especially after scoring. We did not have to rush it and we had a bit of freedom and enjoy it a bit more.
When asked about beating Alessandro del Piero's record to score 20 goals in fewest games, Kane continued: "Not a bad player to beat. It was about qualifying, no matter how we did it but we had to win and we did that. We can enjoy it and try and deep the momentum for Saturday."
