"Don't ask me how I am," Gebrselassie said on Sunday . "It's very special, spectacular."
Gebrselassie trailed the record mark by six seconds at the halfway point, but picked up the pace over the last 10 kilometres (six miles), when he ran alone without pacemakers.
He ran through the giant pillars of the Brandenburg Gate in central Berlin and broke into a smile over the final metres of the race as it became clear he would break the record on his second attempt in the city.
Then he threw his arms up in triumph as he crossed the finish line.
The world record was the 25th for Gebrselassie and the sixth time the marathon world record has been broken in Berlin.
Less than ten minutes after breaking the record, Gebrselassie was handed a cell phone - it was Tergat calling from Kenya to offer his congratulations.
"I'm sorry," Gebrselassie told his great rival and long-time friend. Tergat, who was pipped for the gold medal in the 1996 and 2000 Olympics by Gebrselassie in two classic 10,000 metres battles, would have none of it, telling Gebrselassie he was delighted for him.
Gebrselassie tried to tell Tergat he thought he had better weather conditions this year compared to 2003, when it was sunnier and warmer, although there was less wind, but Tergat responded that records were meant to be broken.
"I really wanted to do this record but I was a little bit worried about it, worried about attacking my friend's record," said Gebrselassie, who fell 61 seconds short a year ago in Berlin in his first attempt to break Tergat's mark.
The Ethiopian distance star confidently attacked the flat, fast course under ideal marathon weather conditions and had split times that were consistently a half minute faster than Tergat for almost the entire race.
Gebrselassie admitted he had been a bit rattled by heavy rain and strong winds in Berlin earlier in the week.
"I lost some confidence when I first arrived, you know, the weather," he said.
"Yesterday, I thought 'what's going on here in Berlin?' But they kept telling me the weather forecast was 'no rain'. How do you believe that?"
The weather forecast turned out to be accurate, with the rain stopping before the race and temperatures at the start around 13 degrees Celsius.
There was only a little wind and skies remained overcast until late in the race.