Hamilton-born distance runner looked strong early on in the 42.195 kilometre race, and stayed in the mix as the lead pack slowly shrunk. With 11 kilometres to go, he made a surge, setting the tempo and leaving only five runners remaining at the 35 kilometre mark.
With the finish line nearing, and a trio of runners left in front, Robertson was dropped, but he paced himself well to claim third place, and the national record.
Ndirangu - also in his marathon debut - finished 23 seconds ahead of fellow Kenyan Albert Korir, with Robertson a further ten seconds back.
Robertson is set to participate in the 10,000 metres at the Commonwealth Games in April, after being named as a late addition to the athletics team last month.