Dakonam was in action for his 31st league outing of the season and put in a decent defensive shift for Jose Bordalas' side until his sending off in the 74th minute.
Earlier Sevilla was reduced to 10 men after Sergio Escudero received two yellow cards in the first half. Then the Togolese defender evened the numbers after he was given his marching orders for an aggressive challenge on Jesus Navas.
Before his sending off, Jaime Mata's effort and Jorge Molina's brace had already given Getafe a three-goal lead that strengthened their push for Uefa Champions League football next season.
The victory at the Coliseum Alfonso Perez moved the hosts ahead of Sevilla to fourth in the La Liga table with 54 points from 33 games.