That assured the American side a half point, and that was enough to give them the 14 1/2 points needed to win the Solheim Cup.
'It's like a dream,' said American captain Nancy Lopez. 'They were ready. It's been a great team effort this whole week. The players played their hearts out.'
'It's unbelievable to play for your country,' said Mallon, who became the all- time leading point earner in American Solheim Cup history this week with 2 1/2 points. 'These fans have been amazing this week.'
The U.S. side got out early and convincingly with a strong start. They took the first five matches, but had to wait anxiously as the bottom of the board filled up with some European flags.
After Natalie Gulbis finished off Maria Hjorth, 2 and 1 in the seventh match, the U.S. had 14 points. They needed a half point, but Europe was ahead in most of the final matches.
The only comfortable lead the Americans had belonged to Mallon in the penultimate match. She was 3-up with five to play and Stupples certainly made it interesting with an amazing par at the 14th that halved the hole.
At the 15th, Stupples landed in a front bunker with her second and blasted out to tap-in range. Mallon conceded the birdie and missed her try from 15 feet so Mallon fell to 2-up with three to go.
Neither player had a great look at birdie at the 16th, but Mallon went first from 30 feet and missed 6 feet left. Stupples came closer than Mallon and was conceded par.
Mallon stroked in the 6-footer to save par and halve the hole. That won the Solheim Cup back for the Americans after losing the trophy two years ago in Sweden.
'What a great feeling,' said Mallon, who was in the opposite spot in 1992 when Europe clinched the Solheim Cup in her singles match. 'I'm so proud of these guys today. We had to play exceptional to beat them. What a match.'
Mallon went on to post a 3 and 1 victory.
Juli Inkster collected three wins in a row from the 13th to dispatch Sophie Gustafson, 2 and 1 in the opening match, but the youngest Solheim Cupper ever put the first point on the board for the Americans in the second match.
Paula Creamer, 19, completed a 3-1-1 debut at the Solheim Cup with a 7 and 5 thumping of Laura Davies, the only player to participate in every competition since its inception in 1990.
Pat Hurst won three in a row from 14 and bested Trish Johnson, 2 and 1, Laura Diaz trounced Iben Tinning, 6 and 5, and rookie Christina Kim dismantled Ludivine Kreutz, 5 and 4.
The rookies stepped up big for the American side. In total, the three first- timers (Creamer, Gulbis and Kim) went 8-3-2.
'They're not rookies to me, they played like veterans,' said Lopez. 'I knew I had to use them, they were my best players coming in here. I had to trust them and I knew they could do it.'
Annika Sorenstam, the No. 1 player in the world, put the first point on the board for the European side in match six. She beat Beth Daniel, 4 and 3, but Gulbis countered the point in the next match.
Europe rallied because the next half-point would give the Americans the Cup.
Catriona Matthew won four out of five holes on the second nine to defeat Wendy Ward, 3 and 2. Carin Koch won three in a row on the back side to handle Michele Redman, 2 and 1.
In one of the biggest upsets Sunday, European rookie Gwladys Nocera, who was 0-1 heading into Sunday, knocked off Cristie Kerr, who earned the most points in qualifying for the American team, 2 and 1.