Michael Phelps reasserts authority with his 16th Olympic gold

Michael Phelps enjoys the victory over his friend Ryan Lochte (EPA)

The total now stands at 16 and this one was all his own work. Michael Phelps claimed his first individual gold of London 2012 last night with a devastating swim in the 200m individual medley that proved too much for a tiring Ryan Lochte. Phelps, the master of Beijing, has reasserted his authority in the pool.

In the head-to-head between the two team-mates and friends it stands at 1-1, Lochte having won the 400m medley on opening night.

But whereas Lochte is struggling with the demands of a programme which saw him pull out of his seventh and final event, Phelps has improved as the workload has heightened with the passing days.

Phelps has two events left. Their tally stands at two gold and two silver for Phelps; two gold, two silver and one bronze for Lochte. Much had been made of Lochte's intensive training regime, designed to equip him to compete across the week, but last night was a task too far.

He faced two finals in 31 minutes. In 1976 in Montreal Kornelia Ender won two Olympic golds in the space of just 27 minutes but the East German was competing at the height of her country's ruinous doping regime.

Neither went to plan for Lochte. In the 200m backstroke he led from the off and a trademark final turn – he is unmatched at the art – appeared to make gold his for the taking.

Instead he tied up and could not prevent his compatriot Tyler Clary and Japan's Ryosuke Irie surging past over the final 10m.

Lochte's first reaction? "He just looked at me and said, 'Good job'," said Clary.

His second reaction was to take to the diving pool that lies behind the main pool at the Aquatics Centre, the first swimmer to do so. He cut a weary figure as he swam slowly up and down while the semi-finals of the women's 200m backstroke played out.

It made no difference. Phelps produced his best performance of the week. He was ahead after the first 50m, the butterfly, and it was a lead he was never to lose.

Phelps won by 0.63sec in a time only 0.27 outside the world record he set in Beijing.

Lochte had enough to consign Laszlo Cseh to yet another bronze medal. Britain's James Goddard tired after a good start to finish seventh.

Phelps was not done, and while Lochte received his backstroke bronze medal he too took to the diving pool to ease off the lactic acid in his legs. Next he collected his gold and barely had time to chuck it in his kit bag before his 200m fly semi-final. He won it. It is odds-on gold medal No 17 will arrive tonight.

Rebecca Soni completed her domination of the 200m breaststroke by breaking the world record for the second night in succession.

It was the sixth record of the week as the drought in the wake of the banning of bodysuits at the end of 2009 is breaking quicker than many observers expected.

Another reflection of a tospy-turvy meet is reflected in Soni being the first 2008 champion to defend a title – Phelps was the second.