At the 2009 World Rowing Championships the four's main rivals were the Australian silver medal four from Beijing who had stayed together to avenge the GB victory at the Olympics.

[2] At the 2011 World Rowing Championships in Bled, Slovenia, Gregory raced in the men's four with crewmates Matt Langridge, Richard Egington and Tom James, winning a gold medal ahead of Greece in second and Australia in third.

[2] At the 2012 GB Rowing Team Senior Trials held in March at Eton Dorney, Gregory and crew mate Alex Partridge came second in the men's pair.

[2] Pete Reed, Tom James and Andrew Triggs Hodge, who won gold in the four in Beijing, were all selected along with Gregory for the Olympic season.

[5] One year later he was part of the British team that topped the medal table at the 2015 World Rowing Championships at Lac d'Aiguebelette in France, where he won a gold medal as part of the eight with Matt Gotrel, Constantine Louloudis, Pete Reed, Paul Bennett, Moe Sbihi, George Nash, Will Satch and Phelan Hill.