The Scot scored and assisted in the Eagles' comfortable win over the Irish minnows that also saw summer signing Dwight Gayle get on the scoresheet for Ian Holloway's men
The striker opened the scoring for the Premier League newcomers and also had a hand in the second goal as they brushed aside the Irish outfit.
Kagisho Dikgacoi was included in the starting line-up for Palace, the South African making his first appearance for the club since the Championship play-off final win over Watford in May.
Danny Gabbidon and Jerome Thomas were also included as Ian Holloway's men continue to gear up for their opening game of the new season against Tottenham on August 18.
Dobbie struck the only goal of the first half after 28 minutes, rounding off an intelligent move from the visitors with a calm near-post finish.
The hosts were able to hold out until the interval, but Palace continued in the ascendancy in the second half, substitutes Owen Garvan and Kevin Philips going close as the Selhurst Park outfit demonstrated their superiority.
Waterford's defence were unable to handle Palace's incisive attack, and the visitors claimed the second goal their play deserved after 76 minutes. Dobbie played a neat one-two with Dwight Gayle to allow the latter to double their lead.
Palace then killed off the game in the dying minutes despite making a host of changes, forward Ibra Sekajja capitalising on a defensive error to make it 3-0 after 87 minutes.
Holloway's charges still had time to add a fourth, and they rounded off the rout in injury time as 23-year-old Swede Osman Sow volleyed home.