Sir Mo Farah battled to 10,000m gold ©Getty Images

Sir Mo Farah overcame one of the toughest challenges of his career to produce a tactical masterclass and win the first gold medal of the International Association of Athletics Federations World Championships here.

The British star was tripped twice in the final lap before powering clear to home success over 10,000 metres in 26min 49.51sec.

It marked his fifth successive world or Olympic title over the 25 lap distance as he registered a 10th successive victory in a global outdoor event.

Rarely has he been pushed as hard as today, though, as the field began with a 61 second opening lap before repeated surges ensured a fierce pace.

After a 13:33 opening half, more surges followed as the lead group was whittled down to under 10 in the closing kilometres.

Sir Mo, who has pledged to focus only on the marathon after this season, repeatedly responded by bursting to the front in a psychological attempt to dissuade his rivals.

Britain's Sir Mo Farah was pushed hard before winning his sixth World Championship crown ©Getty Images
Britain's Sir Mo Farah was pushed hard before winning his sixth World Championship crown ©Getty Images

Farah was clearly working hard, however. 

He took the lead as the crowd roared with a lap to go before twice being forced to step into the infield after catching his feet on those of his rivals.

This did little to stop his trademark attack around the final bend, however, producing a 55 second closing lap to come within three seconds of both his own personal best, as well as the Championship record set by Ethiopia's Kenenisa Bekele in 2009.

It brought back memories of his wins here over 5,000 and 10,000m at the Olympic Games here in 2012.

Uganda's Joshua Cheptegei chased him hard before settling for second place in a personal best 26:49.94.

Kenya's Paul Tanui clocked 26:50.60 for the bronze medal.