Olympic Games: Jessica Ennis and Mo Farah go for gold – in pictures

Considering she's within reach of an Olympic medal, Britain's Jessica Ennis looks remarkably relaxed. She's 184 points clear in the race for heptathlon gold after a stunning 200m display at the end of day one. Today she must compete in the long jump, javelin and 800m Photograph: Tom Jenkins for the Observer

Ennis produces a huge long jump in the third round measuring 6.48m (only 3cm short of her personal best) before competing in the javelin (supposedly her weakest discipline) ... Photograph: Tom Jenkins for the Observer

After a quick chat with her coach, she's ready for her final throw Photograph: Tom Jenkins for the Observer

And what a throw it is! She's launched the javelin to a personal best distance of 47.49m Photograph: Tom Jenkins for the Observer

Her main rival, Tatyana Chernova of Russia, looks fierce enough, but Ennis's performance has been so commanding that she can now afford to run seven seconds slower than her personal best in the final event – the 800m – and she will still become the Olympic champion Photograph: Tom Jenkins for the Observer

No wonder she looks happy Photograph: Tom Jenkins for the Observer

In the men's 100m heats, the competition is strong from the off. Britain's young and inexperienced runner Adam Gemili is drawn in the same heat as the Jamaican legend Asafa Powell Photograph: Tom Jenkins for the Observer

And he shocks the field with a thunderous start, eventually coming a close second to Powell. Gemili's time was 10.11 secs Photograph: Tom Jenkins for the Observer

Back from a doping ban, the American Justin Gatlin is also in good form, clocking 9.97 to win his heat Photograph: Tom Jenkins for the Guardian

While his countryman Ryan Bailey runs 9.88 Photograph: Tom Jenkins for the Observer

Dwain Chambers, whose participation in the Games has been uncertain for so long and whose form this season has been sketchy, wins his heat in a season's best time of 10.02. Though the withdrawal of Kim Collins from the heat (Collins being sent home for leaving the Olympic village) may have helped Chambers Photograph: Tom Jenkins for the Observer

So, the big question now is, what time will the reigning Olympic champion Usain Bolt post? Photograph: Tom Jenkins for the Observer

Bolt makes a stuttering start – Britain's James Desaolu has even got the better of him with half the track gone. But Bolt has the stride length to haul in his rivals and ultimately canters over the line in 10.09 Photograph: Tom Jenkins for the Observer

He doesn't look terribly happy with that. But it's safe to say he looks fit enough to run several tenths faster, despite ongoing injury fears Photograph: Tom Jenkins for the Observer

Arguably his greatest rival for the Olympic title is his compatriot Yohan Blake – the winner of this year's Jamaican trials. Blake runs his heat in a time of 10.00 to suggest that he really could challenge Bolt's supremacy if they both reach the final on Sunday night Photograph: Tom Jenkins for the Observer

In the evening session, the men's 400m hurdles semi-finals are first on the bill. There are three Brits taking part - including Dai Greene Photograph: Tom Jenkins for the Observer

He doesn't look particularly comfortable as he leaps the final hurdle; it's as if he's run himself out Photograph: Tom Jenkins for the Observer

In fact he's struggling even to qualify as they approach the line and he comes across in a time of 48.19 Photograph: Tom Jenkins for the Observer

Greene slumps to the track after his run, fearing the worst. He's fourth is his heat and only the top two in each semi-final qualify, plus the two fastest losers. there are still two heats to go so he will have to wait to know if he'll have a place in the final Photograph: Tom Jenkins for the Observer

His fellow Brit, Jack green crashes out in heat two, quite literally Photograph: Tom Jenkins for the Observer

Then Rhys Williams labours to fourth in his heat in a time of 49.63. The good news, at least, is that Dai Greene has qualified for the final as one of the fastest runners-up Photograph: Tom Jenkins for the Observer

In the pentathlon, Ennis runs the 800m supremely and leads from the off Photograph: Tom Jenkins for the Observer/guardian.co.uk

... and she crosses the line ahead of her rivals with her arms bursts wide open - it's gold for Britain! Photograph: Tom Jenkins for the Observer

Ennis looks stunned. What a race - she lead from the front and came home first to complete an awesome two days of competition Photograph: Tom Jenkins for the Observer

The Sheffield star punches the air with delight Photograph: Tom Jenkins for the Observer

And looks overwhelmed as she's draped in the Union Jack Photograph: Tom Jenkins for the Observer

And she's not the only one draped in the flag tonight ... Greg Rutherford has produced a huge leap of 8.21cm followed by a leap of 8.31cm to win gold in the men's long jump! Photograph: Tom Jenkins for the Observer

Next up it's Mo Farah's turn in the men's 10,000m. He's hunting Britain's third track gold in the space of an hour
Photograph: Tom jenkins for the Observer

Farah darts into the lead on the back straight and is metres from victory Photograph: Tom Jenkins for the Observer

And he just hangs on to win from his training partner Galen Rupp Photograph: Tom Jenkins for the Observer

Farah barely knows where to look Photograph: Tom Jenkins for the Observer/guardian.co.uk

He spots his daughter and runs straight for her. Joy all round for the British athletes on what has been an historic night Photograph: Tom Jenkins for the Observer