Jessica Ennis enjoyed the best two days of her life to claim Britain's first ever heptathlon gold medal in the World Championships in Berlin with a performance of sustained brilliance.

Ennis led from start to finish in the Olympic Stadium, winning three of the four events on the opening day - the 100m hurdles, high jump and 200m - and also setting a personal best in the shot to justify her ranking as world number one.

And the 23-year-old from Sheffield comfortably held onto top spot after today's long jump, javelin and 800m to beat Germany's Jennifer Oeser by 238 points with Poland's Kamila Chudzik a further 22 points adrift in third.

"It's been the longest two days of my life but the best. I can't believe it. I'm the world champion, I feel like crying," Ennis said.

"I've dreamt so many times about winning medals and becoming world champion, doing a lap of honour. It's the best feeling in the world. I can't even put into words how I feel right now, it's such an adrenaline rush and such an amazing feeling.

"It's all come round so quick. This year has been the best of my life, this is the icing on the cake. I was at such a low point last year so to come back from that and so strongly, it's amazing."

It was a remarkable performance in only the second heptathlon since a triple stress fracture to her right foot ruled Ennis out of the Olympics in Beijing last year.

She returned to competition with a personal best of 6,587 in Italy in May and improved that to 6,731 here in Berlin to surpass the achievements of compatriots Denise Lewis and Kelly Sotherton, Lewis winning silver in 1997 and 1999 and Sotherton claiming bronze just ahead of Ennis in Osaka two years ago.

"I was so worried, I didn't know how I was going to come back," admitted Ennis, who was only 100 points short of Lewis' British record.

"I didn't know what kind of shape I'd be in and this year has just gone from strength to strength and now I'm world champion."

Ennis led by 307 points after the opening day but that was trimmed to 269 points after the long jump, Ennis jumping 6.29m in the third and final round.

And the margin was reduced further in the javelin despite a solid throw of 43.54m in the first round.

Chudzik threw 48.72m to close within 171 points of Ennis, with Oeser in third ahead of Olympic champion Nataliya Dobrynska.

However, that still translated to a 12-second cushion for the 800m and Ennis was not about to take things easy anyway, charging through 400m in an amazingly quick 61.12s before winning in two minutes 12.22.

"That was just pure nerves, pure adrenaline, and then I just had to hang on and needed to do enough to win the medal," she added. "I knew what times I needed to run and I just went off too fast.

"I was really pleased, it was consistent solid performances (overall) and I also know that I have a lot more to give in most of the events as well. I'm looking forward to next year and the year after. I'm 23 now and hopefully have a good few years left in me and can crank up a few more points.

"It's about staying injury free now and getting on with it. Hopefully I've had my worst injury, touch wood."