"Its the perfect venue for our sport - a good size arena makes for a more dynamic competition and that's what we got today," said US Reining Chef d'Equipe Jeff Petska.
US rider Tim McQuay was fourth into the ring with his palomino Hollywoodstinselstown, and his score of 220.5 held the lead until bettered by team-mate Craig Schmersal riding Yellow Jersey who was awarded a score of 224.0 by judges Thiago Boechat, Patti Carter, Greg Darnell, Ralk Heselshwitch and eugene Latorre.
Two rides later, Schmersal pushed his American team-mate down to third when slotting into runner-up spot with the 12 year old Mister Montana Nic. "He was so good," Schmersal of his horse afterwards. "He's a veteran now and he came through for me today, just like he always does".
Jeff Petska described the test set for competitors in this first stage of the Reining contest.
"We describe each routine as a pattern, and each pattern includes a set of manoeuvres - there were seven manoeuvres today. They included a right-spin four times, left-spin four times, two long fast circles and small slow circles - these are judged on how easily horses slow down. There was a flying lead-change at the centre-line and judges were looking for the horse to be quiet and under control after the second lead change.
"On the final run the horse should build his canter - like setting up an airplane for take-off - then speed up before the sliding stop. There was a roll-back in which the horse needed to be relaxed and a sliding stop followed by a back-up" he explained.
Petska also pointed out "if you stray too far from what you are required to do then you can end up with a zero score" - and that happened to four of today's starters.
However, for Germany's number one rider it all fell apart at the very beginning. Last to go before the lunch-break, Nico Hormann was executing his opening right-spin with Mister Dual Spring when the 12 year old chestnut lost his footing and fell. Hormann could have continued, but sensibly decided there was nothing to be gained and so retired, thus reducing the German team to just three. However his fellow-countryman, Grischa Ludwig, didn't allow that to deter him and, last into the ring, he scored 220.5, to join McQuay in equal-third place.
Ludwig, who was the last rider of the day, admitted to having some nerves as he entered the World Equestrian Games arena, but midway through his run, he was actually smiling.
"When I saw the second stop there, I knew, exactly, we were going to have a good run. And then I was trying to get the German corner [of fans] a little bit loud," he said.
The adrenaline even got to veteran rider McQuay, who earned a team gold and individual silver at the 2006 WEG in Aachen, Germany.
"When I quit getting nervous, I won't do it anymore," he said.
Massignan described the Alltech arena as "a great colosseum with first-class ground conditions - this place is beautiful and we couldn't ask for anything more".
The 38-year-old rider talked about his early days competing in Italy where the sport of reining "was not so popular", but how he followed his passion and went to work in a yard in Northern Italy before going to the US where he trained and worked for eight more years. "I'm so happy to represent Italy here in this beautiful country today," he said.
Yellow Jersey, a 6-year-old American Quarter Horse stallion by Wimpys Little Step and owned by Arcese Quarter Horses USA, was the winner of the 2009 Italian Reining Horse Association Level 4 Open Derby.
"He's an easy horse, but he has a big heart, a big mind," Massignan said. "He's phenomenal. You can make that go-round if you ride a special horse (and) he's special - for the rest of my life."
One other competitor who stole a lot of the limelight this morning was dressage super-star Anky Van Grunsven from The Netherlands, who recorded exactly the same score as team-mate Fenna Elzinga to slot into equal-14th position.
Talking after her performance with her seven year old palomino Whizashiningwalla BB, van Grunsven said she thought about riding cautiously today but then decided to "just go for it!"
She said she knows her spins need improvement but was very happy with her all-round performance which included two exquisite flying changes.
"It's fun and I really enjoy it and the atmosphere is fantastic," said the woman whose trophy cabinet is weighed down with the awards she has won in the dressage arena over her long and successful career.
The reining competitors are back in the arena tomorrow morning at 7.30am (local time).
Reining Day 1:
The US team are defending champions
28 riders competed in today's first qualifying leg
4 finished on a zero score
The overnight leader is Italy's Stefano Massignan (Yellow Jersey)
The American team holds the lead followed by Austria in second and Belgium in third
The sport of Reining was first included in the FEI World Equestrian Games in Jerez, Spain in 2002.
Teams - 1, USA 444.00; 2, Austria 432.50; 3, Brazil 425.00; 4, Belgium 424.50; 5, Netherlands 422.00; 6, Mexico 420.50.