PD Finn was stabbed in the head and chest while on duty in Stevenage, Hertfordshire, in October.
He had life-saving surgery followed by 10 weeks of recuperation and only returned to work on Monday.
His handler, PC Dave Wardell, tweeted to say: "OMG the legend is back" after Finn tracked a suspect who was hiding.
The pair had been called to Elstree at 21:30 GMT on Tuesday to reports of a vehicle allegedly failing to stop for officers before crashing.
Finn ended up tracking across fields and found a man hiding in an outbuilding.
He was arrested on suspicion of dangerous driving, failing to stop for police and driving other than in accordance with a driving licence.
"Muddy boots, happy dog, happy handler = prisoner in the cells," one of PC Wardell's later tweets said.
PC Wardell has looked after Finn since the German shepherd was nine months old and said his recovery was "testament to his fighting spirit".
Following the suspect's arrest, PC Wardell said there had been "tears of happiness" about how well Finn had done and the rollercoaster of emotions over the last few months.
A petition to bring in tougher sentences for people who attack police dogs - known as Finn's Law - was signed by 120,000 people.
Currently, those who attack police dogs and horses are prosecuted for causing criminal damage but campaigners want the animals to be given the same status as injured officers.
In November, policing minister Brandon Lewis said new legislation could be brought in next year.
A police dog who nearly died after being attacked while chasing a suspect has helped make an arrest on his first day back at work.