Ouseph, who failed to make it out of the group stages of the men's singles at the London 2012 Olympics last summer, held at Wembley Arena, was given a bye into the second round.
And the 27-year-old, seeded fourth, beat Vitaly Konov of the Ukraine 21-12, 21-12 in his first match to progress to round three where he'll face Hsu Jui Ting of Taipei.
Ting beat English teammate Rhys Walker to set up a clash with Ouseph, who is determined to perform to the level his seeding would suggest in London and reach at least the semi-finals.
"I'm obviously seeded to get that far, so it's possible, but I just need to take it round by round," said Ouseph, who won a sixth successive national title back in February.
"It was the first time I've played a match in the hall, so it was a bit difficult in the very beginning, just seeing how the shuttle flew around.
"So I was just trying to get used to it as much as possible. But after that I was quite comfortable from halfway through the first game."
Elsewhere on day two of the London Grand Prix, Kirsty Gilmour won her women's singles first-round clash with Simone Prutsch while Sarah Walker was given a walkover against Beiwen Zhang.
And, remaining with the women's singles, Sarah Milne defeated English compatriot and qualifier Chloe Birch to reach round two; both having represented Team GB in Youth Olympic competitions.