Ellie Simmonds put the disappointment of her 100m freestyle behind her to secure her place in the 400m freestyle at August's IPC World Championships.
The four-time Paralympic winner clocked five minutes 39.78 seconds, under the qualifying time by less than a second at the British International Disability Swimming Championships in Sheffield.
Simmonds, 18 was two seconds slower than the S6 100m qualifying time.
She will now need a discretionary place for the 100m event.
The 2013 IPC Swimming World Championships take place in Montreal, Canada from 11-17 August.
Simmonds, who is competing in five other events in Sheffield, admitted that her training may have been affected by her media activities.
"Having three months out of the water, and focusing on media stuff is a great opportunity, but at the moment it's having a bit of an impact," she told BBC Sport.
"My coach and I will get back and focus hard on all of my events now but this year is also a learning curve after the Games, trying out six events - so I've added two since the [London] Games.
Simmonds added: "It'll be a busy World Championships but hopefully it's going to be a good one as well."
Paralympic champions Jessica-Jane Applegate, S14, and Josef Craig, S7, won their respective 200m and 400m freestyle finals.
The women's 400m freestyle multi-classification final was won by Hannah Russell, 4:42:51, with Tully Kearney claiming silver and Simmonds third.
Applegate's 200m freestyle time of 2:12:21 was a new British record and an impressive return to form for the Norwich-based swimmer who was fifth in Thursday's 100m backstroke final.
Craig, 16, claimed overall victory in the men's 400m freestyle final and his time of 4:43:02, which gave him a total of 998 points, was just outside of the world record.
In the same race Oliver Hynd, 4:30:65, won the battle of the brothers, finishing eight seconds clear of Beijing Paralympic champion Sam and well inside the World qualification time.
It was an eventful day for Stephanie Slater who swam as an S9 swimmer in the morning's heats but was re-classified in the lower S8 category - for those with more severe disabilities - for the evening's 100m butterfly final.
In her revised division the 22-year-old former able-bodied national swimmer claimed a European and British record as well as a World Championships qualification time of 1:11:03.
S9 swimmer Amy Marren, who won her first senior title on Thursday in the multi-disability 100m freestyle and claimed bronze in the 100m backstroke to qualify for both events at the Worlds, continued her impressive championships with silver in the 100m butterfly.
However, the 14-year-old's time of 1:12:14 was not quite quick enough to secure guaranteed selection in that event.
World champion Jonathan Fox, 21, took a step towards the defence of his world title with gold in the 100m backstroke.
S7 Paralympic champion Josef Craig, 15, beat Fox to claim gold in the 100m freestyle.
Andrew Mullen, 16, broke his S5 British record in both heats and finals on his way to his first senior title in the 50m backstroke.