Ethiopia's Tirunesh Dibaba and Tomasz Majewski of Poland both defended their Olympic titles on the opening day of athletics on Friday, but it was British poster girl Jessica Ennis who stole the show.
Dibaba produced her devastating trademark kick 600m from the line to claim a convincing win in 30min 20.75sec over Kenyans Sally Kipyego (30:26.37) and world champion Vivian Cheruiyot (30:30.44).
Dibaba's achievement meant she matched her cousin Derartu Tulu in becoming the second woman to win two Olympic gold medals in the women's 10,000m. It also meant that Kenya have still never won the event.
"I have never been happier," beamed Dibaba. "I was not even that happy after the Beijing Olympics.
"It's very special. I've worked very hard for this. No one has ever done what I did today. I've won two 10,000 golds and one 5000m."
Dibaba, however, was beaten to the first athletics gold of the London Games by Majewski, who became the first thrower since American Parry O'Brien in 1952 and 1956 to retain the Olympic shot put title.
The 30-year-old threw a season's best of 21.89 metres to beat Germany's world champion David Storl by just three centimetres, with American Reese Hoffa taking bronze with 21.23m.
"It's hard to tell which is the most special gold for me. It's different but I am very, very happy now," said Majewski, who hoped his victory would boost his Polish teammates.
"What I do know is that this is welcome for the team as it has won not much yet, so this will be probably very big."
But in a raucous, sell-out 80,000-capacity Olympic Stadium, it was British title hope Ennis who caught the public's imagination, with roars and applause greeting her every move.
The former world champion rode the enormous pressure to set personal bests in the 100m hurdles and 200m to take the overnight lead in the heptathlon.
Ennis beat her personal best by 0.25sec as she set a new British record of 12.54sec in the hurdles, and then clocked 22.83sec in the 200m to leave her on 4,158 points, 184 ahead of second-placed Austra Skujyte.
To put Ennis' hurdles time into perspective, it matched American Dawn Harper's winning time in the individual hurdles at the Beijing Games in 2008.
Defending Olympic champion Natallia Dobrynska of Ukraine was in 10th position on 3,835pts, 323pts off Ennis, with Russian world champion Tatyana Chernova down in ninth on 3,849pts.
"I'm absolutely made up with today," said Ennis, who will negotiate the long jump, javelin and 800m on Saturday. "To perform like that with two personal bests was a brilliant start.
"It's a combination of a hard, fast track and obviously it's the Olympics and having this huge crowd behind everyone makes a huge difference.
"I knew coming into this I was in good shape but to be honest I couldn't have imagined performing like this. I've definitely exceeded my expectations today."
American world champion Carmelita Jeter fired a warning to Jamaica's sprint queens as she seeks to become the first US woman to win the 100m since Gail Devers in 1996.
Jeter qualified quickest for the semi-finals in a blistering time of 10.83sec, which would have won a silver medal at the 2008 Beijing Olympics.
Jamaica's Veronica Campbell-Brown, a two-time Olympic 200m champion and 100m world champion in 2007, clocked 10.94sec with teammate and defending Olympic champion Shelly-Ann Fraser-Pryce seventh fastest with 11.00sec.
The semi-finals and final take place on Saturday.
"I just had to come out and execute like my coach wanted me to do. I still have two more rounds to go. Everybody's going to definitely be running their hearts out tomorrow," said 32-year-old Jeter.
There was heartbreak for Panama's defending Olympic champion Irving Saladino, however, as he failed to register a mark in the long jump, blaming the wind and lack of training afer four months' out following knee surgery.
"I'm not disappointed. I only came back into training in April," he said.