Samaras scored from an overhead kick 16 minutes into a one-sided first half but Forster needed to be alert to keep out Colin Nish's header five minutes after the break. Celtic secured their fifth consecutive Clydesdale Bank Premier League win - and moved seven points clear - after Hooper lobbed Rab Douglas in the 71st minute.
Celtic manager Lennon said: "I'm pleased with the performance on a difficult pitch, it was quite rutted and bobbly. We have to adapt at times better to the conditions but we had two real bits of quality to win the game."
He added: "I had to rely on my goalkeeper to make a fantastic save. We have seen that time and time again - it was another wonderful point-blank save. Thankfully he was able to keep a clean sheet and we went on to win with a superb individual goal again from Hooper."
Meanwhile, Lennon defended Kelvin Wilson after television pictures showed the centre-back had caught Dundee striker John Baird with an arm late in the first half. Baird needed treatment but referee Iain Brines took no action over the off-the-ball incident.
Lennon had not seen it but said: "What he is saying is the guy had hold of his arm and he has basically pushed his hand away. The boy Baird was nipping away at the players all night and barging into them.
"Now, if Kelvin has been deemed to have acted badly retrospectively, we will deal with it if and when it comes. But our discipline has been excellent and Kelvin has been a model pro since he walked in the door, and it's not like him. So I'm pretty sure if it does look bad then it's not deliberate."
Dundee manager Barry Smith, who did not see the incident with Wilson, was encouraged by the bottom club's second-half display.
Smith said: "We said to them at half-time, they had defended relatively well and made it difficult for Celtic but we needed them to be a wee bit braver on the ball and I think in the second half they came out and did that.
"At 1-0 the keeper has made a world-class save and you don't know what would have happened if it had gone to 1-1. But the players kept fighting away and we're happy with the performance in terms of keeping the ball for a good 20-25 minutes anyway."
- Sports & Recreation
- Clydesdale Bank Premier League
- Kelvin Wilson