Kayal scored his side's all-important second goal in the Group H showdown with the Dutch giants at Parkhead last night.
However, the Israeli internationalist reckoned it was Forster who was responsible for the Scottish champions picking up their first points.
The English shotstopper was absolutely outstanding once again in Europe's premier club competition and pulled off a string of important saves throughout the night.
Kayal said: "After the game against Barcelona I was asked how good he was and I replied: 'He is amazing!' We are so glad that this keeper plays with us.
"He is a big, big player for us. He proves himself in the Champions League game after game. He was the man who helped us win the three points last night.
"We have a lot to thank Fraser for.
"I am so happy for the team that we managed to get three points in our third game.
"We played well in the last two games against AC Milan and Barcelona and didn't pick up any points. But against Ajax we worked hard as a team and we got a great win."
Forster's blocks, including a fabulous stop to deny Thulani Serero, ensured Celtic triumphed 2-1 and kept alive their hopes of qualifying for the knockout stages of the tournament for the second season running.
Spanish cracks Barcelona top Group H on seven points after drawing 1-1 with AC Milan - who are in second place on five points - in Italy last night.
Celtic are in third place on three points thanks to their deserved win over Ajax who are in bottom spot with just a single point from their three outings.
Kayal, who did well after replacing suspended Hoops captain Scott Brown, is confident they can beat the Dutch away in Amsterdam in their next match next month.
He said: "The dream is still there. But we need to win the games step by step. It was a big push for us to get all three points. We are now just looking forward to the next game.
"In the first half we tried to be more tactical, to work as a team, to stop Ajax playing their normal game.
"That gave us more confidence in the second half. We managed to play far better.
"I think we need now to focus on the next game in the league. But I hope that a few players who are injured come back to the squad for the next Ajax game.
"We will go over there and try to do the job also. Hopefully we can win the game. I am sure that if we play as well as we did at Parkhead we can achieve this."
Kayal scored in 53 minutes after his shot took a massive deflection off Ajax player Stefano Denswil and flew beyond the clutches of keeper Jasper Cillessen.
It was the 25-year-old's first goal for Celtic since he scored in a 4-1 win over Dundee United back in May of 2011.
He was delighted to get his name on the scoresheet in such a big match - and was unconcerned with how the ball made it into the back of the net.
He said: "I was so, so happy to score. But the important thing is the three points for the club.
"I don't know if it took a deflection. I just saw the ball in the back of the net. It was important as it helped the team to get a victory and keeps our dream alive."