Sarah Sjostrom, who has been winning world titles for 13 years, and Summer McIntosh, who has been winning them for four days, both collected their second gold medals of the week in Budapest on Saturday.
Ms. Sjostrom, a 28-year-old Swede who won the 50m butterfly less than 24 hours earlier, added the 50m freestyle, her 10th world gold.
Ms. McIntosh, a Canadian 15-year-old, held off 16-year-old American Katie Grimes to win the women's 400m medley title.
