One second. 

That’s the time represented by 0.4 penalties in eventing, and that blink of an eye is the margin by which Liz Halliday and Miks Master C, the horse who finished third in his five-star debut in Kentucky earlier this year and with whom she recently was named to the U.S. Eventing Team for the upcoming Pan American Games in Chile, won the $60,000 Adequan USEF Advanced Final on Friday at the USEA American Eventing Championships.

It was an unexpectedly hold-your-breath-and-wait finish for a pair who started the competition on top of the dressage leaderboard and maintained a one-rail-plus lead over their closest competitor—seven-time Olympian Phillip Dutton and his Tokyo Olympics partner Z—all the way until the final fence on the show jumping course.

Double-clear show jumping rounds had been hard to come by throughout the division, with only four among the 25 pairs who had tackled Bobby Murphy’s course before Halliday and “Mikki,” an 11-year-old Swedish Warmblood gelding (Mighty Magic—Qui Luma CBF, Flyinge Quite Easy 958) owned by Ocala Horse Properties LLC and Deborah Palmer, entered the ring. Those four came from Halliday and her other mount, Deniro Z, giving the sense she’d already discovered the key to a clear round, and Dutton on all three of his advanced rides, including Z and Azure—sitting in second and third places after cross-country respectively—to put the pressure on the leader. 

Halliday had opened the week by scoring a 23.1 in dressage with Mikki, giving her a 4.4-point lead over Dutton and The Z Partnership’s 15-year-old Zangersheide gelding Z, who slotted into second place with a 27.5.

Watch their dressage test, courtesy of Horse & Country TV:

Halliday then used Jay Hambly’s cross-country track to give Mikki a good experience and prep run for the Pan Ams, coming up in October. 

“He’s an amazing horse,” Halliday said after cross-country. “He made everything feel very easy. He was with me the whole way. I had a little moment when some people ran in front of me in front of a jump, so I actually slowed him up a bit at the end. I think I would have made time otherwise.”

They added 3.2 time penalties to Z’s 4, opening their lead to 5.2 points and meaning they would go into Friday’s final show jumping phase with the equivalent of one rail and 3 seconds of time in hand.

Watch their leading cross-country round:

Entering the Kentucky Horse Park’s Rolex Stadium in the low, late-day sun, it turned out they would need every bit of it to hold onto the win. Their round looked polished and perfect to the very last liverpool, which Mikki hit. Suddenly her one-rail cushion was used, as were some or all of the 3 seconds that kept her ahead of Dutton. Halliday and the crowd waited at attention while the numbers were verified and the announcement came: She was 2 seconds over time and would finish on a final score of 31.1 to Dutton’s 31.5, holding onto her weeklong lead by the slimmest of margins.

“I am totally thrilled—I’m obviously going to have anxiety for the next 10 years after that,” she said afterward. “I knew I was right on the edge, and when they announced my score, I had a moment where I was like, ‘Maybe I did the math wrong.’ I was freaking out a little bit, like, ‘That was cutting it too fine, Halliday.’ He just jumped phenomenally the whole weekend. 

“I think that light’s a little funny in there [at the liverpool], and he just saw a glare in the water tray as he took off,” she added, “and I was shocked because he was jumping so well.”

Watch the show jumping round that clinched their victory, and highlights of the awards ceremony after:

Ahead for the pair is the Pan American Games, the eventing portion of which will be at the three-star level and held Oct. 28-29 at the Escuela de Equitación Regimiento Granaderos in Quillota, Chile. There, they’ll join the rest of the U.S. Eventing Team named Aug. 23.

 “I think it will be a great opportunity to ride around [a course by] the course designer from the Olympics with him because I hope he’s my Olympic horse,” she told USEA. “Mikki’s done a lot of amazing, big things in the last year. I think it will be really useful for him ahead of next year.”