In the sensational 15-run victory, Mahmudullah scored 103 runs, becoming the first Bangladeshi to hit a World Cup century. Mushfiqur hit a solid 89.
Mahmudullah married Bhuiyan and Akther's daughter Jannatul Kawsar Mishti in 2011. Mushfiqur married their younger daughter, Jannatul Kifayet Mondi, last year.
"I was waiting for this day. I knew that his good days will come. He worked hard before the World Cup," Bhuiyan told Bengali daily Prothom Alo about his centurian son-in-law.
"Whenever Mahmudullah came home before the World Cup, he refused to eat anything. He used to say if he did well in the World Cup, he will eat at our house for seven days at a stretch," the proud father-in-law said.
Akhter added: "I always love watching my sons-in-law play."
Asked if she feels sad that her younger son-in-law missed the century by 11 runs, she said: "I have no regrets. Both my sons-in-law performed well today and contributed to the team's win."