Gibney, a junior from Australia, held tough on the last lap when seven teams had a legitimate shot at winning. He made his move against BYU anchor Miles Batty, the NCAA indoor champion in the mile, and brought the Wildcats home in 9 minutes, 37.93 seconds.
That might have been the slowest winning time at the carnival since 'Nova clocked 9:43.6 in capturing the 1973 DMR, but O'Sullivan didn't care.
"I can't tell you how proud I am," he said. "It was just phenomenal for me to watch it, and it was just an incredible experience for me as a coach to watch something as exciting and thrilling."
The Wildcats' two first-time runners both were local - junior Brian Tetreault (1,200 meters) of Cinnaminson High and freshman Samuel Ellison (800) of Upper Dublin High. They joined sophomore Carlton Bowers and Gibney, who also anchored the 2009 team, on top of the victory stand.
The men's DMR was one of the two longest races, both of which produced stirring finishes.
The crowd of 38,806 watching the women's 4x1,500 was cheering Villanova's Sheila Reid as she tried to chase down Georgetown's Emily Infeld in the final 200 meters. But Boston College's Caroline King came out of nowhere to pass both Reid and Infeld and carry the Eagles to their first-ever carnival triumph in a women's Championship of America event.
"It was so exciting, definitely the most exciting race I've ever been in," said King, a senior who won the Atlantic Coast Conference 800-meter championship last week.
The Villanova men had their DMR lineup all squared away when senior Jason Apwah, the scheduled 800-meter man, suffered a pulled hamstring Tuesday. After consulting with his staff, O'Sullivan decided to move Ellison from the 400 to the 800 and insert Bowers, who ran the 400 in the NCAA indoor DMR, on the shortest leg.
Bowers clocked 46.89 seconds in the 400, and Ellison came in at 1:51.03 before handing off to Gibney one stride behind pacesetting Arkansas.
Gibney elected to stay back in second or third place rather than seize the lead. With 400 to go, he was within striking distance of Albany, but Arkansas, BYU, and Indiana all had strong kickers, and the wait was to see who would break out of the pack.
"You can sort of tell when how well they're going and how much they've got left," Gibney said. "Normally when you're getting that close to the end of a slow race, if there are people ready to go, they're getting as close to the front as they can before they stride. I guess there wasn't the pressure there I expected so that made me feel confident."
O'Sullivan wasn't sure how much Gibney had left as he reached the final straight, then he found out.
"I started to realize he's got so much more left," he said. "He only had one race under his belt coming into Penn, which was last week, so I was a little uncertain about his speed."
Gibney came in triumphant, thrusting both fists in the air at the finish before being mobbed by his teammates.
Arkansas took second at 9:38.40 with BYU, the NCAA indoor DMR champion, third in 9:38.60.
It was the same kind of stirring finish as the women's 4x1,500. Georgetown, winner of Thursday's women's DMR, took the baton for the anchor leg with a 20-meter lead over Boston College and 30 over Villanova.
All three anchors went out quickly, but Infeld's advantage gradually closed as the contenders reached the final lap. Reid was in full sprint on the final turn but King passed her, and then caught Infeld for a narrow win. The Eagles were timed in 17:25.19, with Georgetown coming in at 17:25.65, and Villanova in 17:28.12.
It was another disappointment for the Wildcats, who dropped the baton in the women's DMR, even though Reid clocked 4:13.4 on her leg.
"I wanted more from myself for the team," she said. "It was a little too close for comfort. Yesterday was heartbreaking but some stuff is out of your control. I felt like this was a little more in my control, and I let it slip away, so that's a little more difficult to deal with."
Contact staff writer Joe Juliano at 215-854-4494 or firstname.lastname@example.org