Ecuador's Brian Pintado won the first athletics Olympic gold medal of the Paris Games on Thursday with victory in the men's 20-kilometre walk.

Brazil's Caio Bonfim improved on his fourth from Rio in 2016 taking silver with Spain's world champion Alvaro Martin taking the bronze.

It was Ecuador's second Olympic title in the event after Jefferson Perez's gold medal at the 1996 Atlanta Games.

Pintado appeared to be clutching a family photograph as as he crossed the line before being connected to loved one via a live link.

The race was delayed half an hour due to a thunderstorm but once they started at Trocadero, Bonfim took off as if he wanted to make up for the lost time.

The 33-year-old and his rivals may not have had the time to take it in but for spectators and viewers the race was a splendid spectacle as they did 20 laps, along the banks of the Seine and passing by the Eiffel Tower as well as Trocadero.

He was gradually reeled in but stayed amongst the leaders and was ahead at the halfway mark.

He only held a slight advantage and the lead began to change on a regular basis with China's Zhang Jun, Spaniard Paul McGrath, defending champion Massimo Stano from Italy and Martin all heading affairs at times.

The field got strung out with many of the walkers getting on the wrong side of race judges and being put into the penalty zone.

The spectators who had turned out at an early hour to watch the event were a colourful bunch, including a vociferous bunch of sombrero-wearing Mexican supporters.

With under six kilometres to go, a group of 10 broke from the pack and spreadeagled the field.

Stano led at the 16km mark but he too incurred the wrath of the judges and received a warning.

The irrepressible Bonfim, however, then injected some pace and split the leading pack.

Just three were able to go with him, Stano, Martin and Pintado.

However, on the penultimate lap Stano's dreams of making history in becoming the first Olympic champion to successfully defend his title evaporated as Pintado moved up a gear.

From then on he ruthlessly dispensed with Bonfim and Martin, who had nothing left in the tank.