Jessica-Ennis Hill began her Olympic title defence in fine fashion with strong performances in the first two events but it is compatriot Katarina Johnson-Thompson who leads following a record breaking high jump competition.
In the first event of the two-day competition, Ennis-Hill demonstrated her dominance in the 100 metres hurdles with a blistering time of 12.84 and 1149 points as the 30-year-old from Sheffield proved the only athlete to go under 13 seconds and take the lead by 25 points.
Johnson Thompson finished in 13.48 and 1035 points to take 11th place but things improved dramatically for the 23-year-old from Liverpool in the high jump.
In what is her strongest event in the heptathlon, Johnson-Thompson produced a huge leap for 198cm for 1211 points to claim a British record and top spot of the completion after two events with 2264 points.
Ennis-Hill was herself in impressive form as she cleared 189cm to take third place overall as she sits just 20 points behind her Team GB teammate with Belgium’s Nafissatou Thiam slitting the pair in second place.
Next up for the duo is the shot put competition and the 200m, both of which take place at the Olympic Stadium this evening.
The first track final of the Olympic Games was the women’s 10,000m and Team GB was well represented with Jo Pavey, Beth Potter and Jessica Andrews all competing.
In an incredible race which was won by Almaz Ayana of Ethiopa in a new world record of 29:17.45, 42 year old Pavey performed admirably as she led the British contingent home in 15th place with a time of 31:33.44.
“I would have liked to have run a bit better but I feel so honoured to have been in a fifth Olympic Games – I feel so fortunate and I gave it my best on the day,” said Pavey. "I would have liked to have run a bit quicker but realistically I am getting very, very old!"
Andrews finished just one place behind Pavey in 16th as she saved her best ever performance for the world’s biggest stage and set a personal best of 31:35.92 while Potter crossed the line in 34th place in a time of 33:04.34.
Elsewhere Michael Rimmer made it through to the 800m semi-finals as he placed third in his heat with a time of 1:45.99 for automatic qualification but Elliot Giles will not join Rimmer as he faded in the closing stages and crossed the line in seventh place in 1:47.88.