The fact they ran their slowest marathons did not diminish the elation they felt when they crossed the finish line.
There were 35,000 starters and Craw (58), an accountant, finished 19,602th in 5hr 07min and Esplin (63), a vocational consultant, was 21,751st in 5hr 30min 23sec.
Esplin has a best time of 2hr 54min 07sec and Craw 2hr 57min.
The elite athletes start at the front, but the runners behind them spend the first 12min walking while they dodge past slower runners on the narrow streets.
It was Esplin's first international marathon.
"It was a thrill to be part of it," he said.
"Spectators were lining the whole route and slapped your hand as you ran passed.
"Bands were playing and there was a carnival atmosphere."
Esplin enjoyed passing the historical sites, such as Cutty Sark at Greenwich and London landmarks such as Tower Bridge, the Tower of London, the Houses of Parliament and Buckingham Palace before finishing at the mall.
The London Marathon was first held in 1908 and the centennial medal given to Esplin and Craw was the reward for the hard training.
Esplin also ran the Indianapolis half-marathon earlier this month on his way home. There were 35,000 starters and he finished in 14,316th in 2hr 25min.
It is the eighth-largest running event held annually in the United States and the entry list was filled by the end of November last year.
Esplin started running when he joined the Dunlaider (now part of Hill City) club 34 years ago. He has now completed six marathons.
He has also run the Kepler Challenge five times with a best time of 7hr 15min, the Milford Track and the Motatapu.
Both Esplin and Craw wore their New Zealand Masters Games T-shirts in the London Marathon.
