( CNN ) -- Ethiopian Tirunesh Dibaba made a successful defense of her Olympic 10,000 meters crown to round off the first night of track and field finals Friday . Dibaba used her famed finishing kick to pull clear of Kenyan pair Sally Kipyego and reigning world champion Vivian Cheruiyot with a 62 second last lap to win in 30 minutes 20.75 seconds . It was the third Olympic gold medal for Dibaba , who is a seven-time world champion and holds the world record for the 5,000m . Dibaba 's teammate Werknesh Kidane pushed the pace after halfway in the grueling 25-lap event to whittle down the medal contenders to two Ethiopians and two Kenyans . Kidane paid for her efforts but an ever confident Dibaba hit the front before the bell and victory was a formality with Kipyego claiming the silver . While Dibaba was doubling up , Poland 's Tomasz Majewski became only the second man in history to retain the Olympic shot put title . The 30-year-old threw 21.89 meters to edge out Germany 's world champion David Storl , who had a best of 21.86m . Reese Hoffa of the United States took bronze with 21.23m . Majewski matched the feat of American Parry O'Brien , who won successive golds in 1952 and 1956 . The Pole took the lead in the third round and finished off in style with his best effort . Earlier , the home crowd in an 80,000 seater Olympic Stadium with few empty seats , had reason to cheer as Jessica Ennis took a commanding lead in the women 's heptathlon . Ennis , the poster girl of the 2012 London Games , set personal bests in the 100m hurdles and 200m on the way to a first day score of 4,158 points , 184 clear of Lithuanian Austra Skujyte . With the long jump , javelin and 800m to go , Ennis has a healthy lead over defending Olympic champion Natallia Dobrynska of Ukraine and Russian world champion Tatyana Chernova , who were 10th and ninth respectively . Britain 's Christine Ohuruogu made a successful start to her defense of the women 's 400m title with a 50.80 seconds clocking to come through in the first round . Her old rival Sanya Richards-Ross of the United States also progressed . Amantle Montsho of Botswana was fastest qualifier in 50.40 seconds . Saturday 's track and field action will see the first appearance for Jamaica 's sprinting superstar Usain Bolt as he begins the defense of the 100m title .
Tirunesh Dibaba wins first track gold of the London Olympics . Dibaba successfully defends her 10,000m crown . Tomasz Majewski retains his men 's shot put crown for Poland . Home hope Jessica Ennis leads women 's heptathlon after first day .