Rosa Pfeiffer won’t ever forget this Mother’s Day present from daughter Sylvia.

Sylvia Pfeiffer gave her mom the home-run ball she drilled in the bottom of the sixth inning that carried Kansas University to a 3-1 softball victory over Iowa State on Sunday at Arrocha Ballpark.

“She’s going to autograph it for me later,” Rosa Pfeiffer said, smiling. “I feel great. This is just the best present.”

Pfeiffer’s mom had flown to Lawrence from Arcadia, Calif., for Senior Day activities. Pfeiffer and five other seniors were honored during pregame ceremonies.

“It was perfect,” said Pfeiffer, a reserve outfielder. “My mother has supported me my whole career.”

The 5-foot-5 Pfeiffer seemed an unlikely candidate to become Sunday’s heroine. She has been in and out of the lineup all season, starting less than half the games, and she was batting in the ninth spot in the order.

“I was hoping coach would start me,” Pfeiffer said. “I expected to start because I’m a senior.”

KU coach Tracy Bunge confirmed she gave Pfeiffer the nod in part because it would be her last game at Arrocha Ballpark and also because regular right fielder Melaney Torres, a sophomore, was gimpy.

“Sylvia deserved to play,” Bunge said. “I couldn’t be happier when a senior comes through in her last home game like that.”

Pfeiffer nearly homered in the third inning, but her drive to left hit halfway up the wall, and she settled for a double. Minutes later, she scored on a sacrifice fly by Heather Stanley.

When Pfeiffer came to the plate in the bottom of the sixth, the score was knotted at 1. With two out and a runner on second, Pfeiffer picked on a 2-1 pitch from ISU reliever Kristen Karanzias and blasted it high on the grass embankment behind the flag pole in left-center field for her fourth homer of the season.

“I knew a senior was going to do it,” said winning pitcher Kara Pierce, also a senior. “I’m so happy for it to be Sylvia.”

Pierce surrendered two hits and a run in the first inning, then gave only one more hit the rest of the way to record her 17th victory in 28 decisions.

Pierce blamed the pregame ceremonies for her slow start.

Kansas University third baseman Sandy Smith throws to first for a force out against Iowa State. The Jayhawks won their Senior Day game, 3-1, Sunday afternoon at Arrocha Ballpark. KU's Destiny Frankenstien, right, backs up the play.

“I was warmed up, then we sat for a long time,” Pierce said. “I felt a lot better as the game went along.”

Bunge probably will use Pierce on the mound Wednesday when the Jayhawks open in the Big 12 Conference tournament in Oklahoma City against bottom-seeded Texas Tech.

If the Jayhawks win the 5 p.m. contest at ASA Hall of Fame Stadium, they’ll have to play No. 2 seed Texas A&M immediately afterward.

KU finished 7-11 in conference play and earned the No. 7 seed. Iowa State, which wound up 3-13, is the No. 9 seed and will meet eighth-seeded Texas on Wednesday.