A truck loaded with hay has literally taken out the finish line of the Tour Down Under (TDU) cycling race in the main street of Gumeracha in the Adelaide Hills.

As the women cyclists raced stage one, ABC reporter Sarah Hancock and cameraman Haidarr Jones got a front-row view of some unexpected action.

The truck drove through the inflatable start/finish line and dragged it along until finally coming to a stop some distance down the road.

Sorry, this video has expired Hay truck takes out finish line as ABC reporter Sarah Hancock records her news report

A couple of spectators also got more than they bargained for at their finish mark vantage point.

Police later said they had not been required to deal with the chaos.

During TDU racing, there is always a rolling schedule of road closures to allow the race competitors to pass through safely.

Some quick repairs are made to the inflatable finish after it was dragged along the roadway. ( ABC News: Sarah Hancock )

By the time local cyclist Annette Edmondson made it over the finish line ahead of the rest of the field, the inflatable signage had been hastily fixed and re-erected by race officials.

More than 100 women took part in the opening stage, with the men's event to be held next week.