Auckland Reactor is a New Zealand standardbred racehorse bred by Dr. Tony & Anne Parker. He was crowned New Zealand Horse of the Year in two seasons. He was also given the nickname The Reactor Factor because most Trainers supposedly feared him.

Auckland Reactor's raceday debut was much anticipated, with efforts at the trials leading many people to label him a top horse in the making. He won his debut at Timaru in September 2007. Three more wins followed before he won his first Group One race; the Sires Stakes 3-Year-Old Championship in November, where he came from an outside barrier draw to win easily. He returned to racing in January 2008 with a win. Another two wins in March preceded convincing wins in the Flying Stakes and the New Zealand Derby. In what was to be his final start for the season, he won the Southern Supremacy Stakes, where he recorded the fastest last 800m of a race ever in New Zealand of 54.0 seconds. This completed an undefeated 11-start season which saw him crowned New Zealand Horse of the Year.

In early May 2008, Auckland Reactor was purchased by an American syndicate for a reported $3.5 million, an unprecedented sum for a New Zealand pacer. Despite the sale, he remained with his original trainers, Mark Purdon and Grant Payne. His final race as a 3-year-old was set to be the 3-Year-Old Emerald, at the Harness Jewels raceday at Cambridge at the end of May. However, he had to be scratched from that race with an injury concern.^[1] That injury was expected to rule him out for the rest of 2008, including the New Zealand Trotting Cup in November.

Auckland Reactor recovered from the injury better than expected, and returned to racing with a win at Ashburton in late October. Connections ruled out a run in the New Zealand Trotting Cup, where he probably would have been favourite, because of his hampered lead-up and lack of standing start ability. Instead, he won the Junior Free-For-All on the Cup undercard, before meeting many Cup starters, including the winner Changeover, in the New Zealand Free-For-All. In the biggest test of his career, he won the Free-For-All in record time, confirming his status as clearly New Zealand's best pacer. A planned clash against Australian champion Blacks A Fake in the Miracle Mile Pace in Sydney was aborted due to the length of time it would take for the horse to return to New Zealand with quarantine issues.^[2] Instead, the horse contested the Franklin Cup at Alexandra Park in Auckland, where he broke the track record for 3200m. His first start for 2009 was in the Waikato Flying Mile at Cambridge, which he won in a time of 1.53.5, equalling the New Zealand record. He returned to Cambridge the following week to win the Cambridge 4yo Classic, taking his record to 17 wins from as many starts.

Auckland Reactor returned to Cambridge for a third straight week to contest the 4yo Futurity Stakes from a standing start. His poor standing start manners proved to be costly. He galloped for approximately the first 100 metres from the race and was tailed off the rest of the field. He managed to catch the field and get a position outside the leader, but he did not have enough energy left in the home straight to run past All Tiger, and his unbeaten record ended at 17. The time of the race (0.8 seconds outside the track record) showed how good Auckland Reactor had to be to get as close to winning as he did.

Auckland Reactor came back to winning form straight away in the inaugural Summer Cup at Addington on 31 January, and followed that up with a win in a minor free-for-all at Addington. He then contested the Auckland Cup, where he drew the outside barrier. After dropping to last at the start, he took the lead a lap from home and went on to win by 13⁄4 lengths, giving him his biggest win to date and taking his earnings past $1 million.

Plans to stand Auckland Reactor at stud for the 2010 season were abandoned after some ownership changes and a willingness to focus on a return to racing. He returned to racing on 12 February at Ashburton, winning in a time of 1:52.9 for the mile (0.8 seconds outside the New Zealand record). However, he finished at the back of the field in his next two starts, including the Auckland Cup, after failing to settle in the running. He was set to contest the Inter Dominion series at Auckland starting 25 March, but was scratched after suffering an attack of Colitis X a few days prior.

Auckland Reactor returned as a 7-year-old on 30 September in the Avon City Ford Cup. He showed little sign of his previous standing start concerns, settling towards the back of the field and finished strongly to win by a head. This was followed by a fast-finishing run for fifth in the Canterbury Classic. He then contested the Ashburton Flying Stakes; a main lead-up race to the New Zealand Trotting Cup. Here, he moved around the field to sit outside the leader with 1000 metres to go, before running clear in the straight to claim a convincing 21⁄2 length win, breaking his last-800-metre record with a 53.8-second time. The performance made him one of the favourites for the New Zealand Cup; however, a hoof injury forced him to be scratched from that race.

Resuming in Australia in January 2012, Auckland Reactor narrowly won the Pure Steel at Ballarat in track record time. This was followed by a close second off a 10m handicap in the A G Hunter Cup.

Auckland Reactor started his preparation for the 2012 New Zealand Cup with two starts at Addington, galloping at the start both times. He finished a strong sixth first-up in the New Brighton Cup, but a disappointing eighth in the Canterbury Classic, after which another hoof injury was found. He recovered to start in the Louisson Handicap at Addington, but interference at the start contributed to him galloping again, with the horse eventually moving to the lead before tiring to run last. Despite these setbacks, he finally started in his first New Zealand Cup. However, his big race bad luck continued when, despite starting well, he tired to finish a clear last and was found to have an infection after the race. After getting over that infection, he resumed racing in the Waikato Flying Mile, where he ran a strong-finishing fourth.

• Auckland Reactor was inbred 4 × 4 to Meadow Skipper, meaning that this stallion appears twice in the fourth generation of his pedigree.

• Auckland Reactor's Official Website
• Auckland Reactor wins the New Zealand Free For All – Youtube