Newport: M4 traffic delays due to Malpas Viaduct repair work
The delay was estimated to be around 30 minutes, but westbound traffic on the M4 was unaffected.
Traffic Wales said the works, which will see expansion joints in the viaduct replaced, were "essential maintenance".
The M4 eastbound is due to re-open at 06:00 on Monday, but this will be followed by three nights of overnight closures for two consecutive weeks and further repair work east and westbound over the next two weekends.
Before the work was cancelled on Saturday, concerns were raised about the disruption potentially affecting rugby fans travelling to Twickenham.