1990: two-year-old season

Fourstars Allstar was placed in his first three races before winning a maiden race at Saratoga Race Course on August 24. He was unplaced in minor stakes events in his next two starts and then won an allowance race at Belmont Park on October 7 at Belmont Stakes. Thirteen days later he was stepped up in class and finished second to River Traffic in the Grade III Laurel Futurity at Laurel Park. He moved to Aqueduct Racetrack for his last three races of the season and recorded his first important success in the Grade III Pilgrim Stakes on October 31, and followed up in the Damon Runyon Stakes five days later. On his final start he failed to finish in the New York Stallion Stakes on December 1.^[2]

1991: three-year-old season

During the winter of 1990/1991 O'Brien, having already decided to aim Fourstars Allstar at the Irish 2000 Guineas, moved the colt to Florida to train on the turf gallop at Tony Everard's Another Episode Farm. Fourstars Allstar began his second season by finishing second in an allowance at Aqueduct in April and then won a similar event at Belmont on May 5, beating the subsequent Grade I winner Solar Splendor. He was then shipped to Ireland to contest the Irish 2000 Guineas on May 18, arriving three days before the race. Although many horses bred in the United States and owned by Americans had won major races in Europe, no horse trained in the United States had won a European classic race.^[6] An additional obstacle was that the race was run around a right-handed (clockwise) circuit: all major tracks in the United States are left-handed (counterclockwise). Ridden by the American jockey Mike Smith he started the 9/1 third favorite behind the French-trained colts Lycius and Ganges who had finished second and third in the English 2000 Guineas. The other fancied runners were the undefeated Kalahari Prince (from the Vincent O'Brien stable), Rinka Das (winner of the Cartier Million), the British-trained challenger Mellaby and Star of Gdansk (Tetrarch Stakes). Racing a set of light blue blinkers the American colt broke quickly from the stalls, took an early lead and maintained his advantage into the straight. Star of Gdansk, ridden by Christy Roche moved up on the inside and went to the front approaching the last quarter mile, but Fourstars Allstar rallied strongly, regained the lead in the closing strides and won by a head. The pair pulled well clear of their rivals and there was a gap of six lengths back to Lycius in third place.^[7]

After returning to the United States, the colt failed to win in seven subsequent starts that season but ran well in several good races. He finished second in the Lexington Stakes and third in both the Gallant Man Stakes and the Knickerbocker Handicap.^[2]

1992: four-year-old season

Fourstars Allstar ran 11 times at age four, winning twice with two second-place finishes and a third. He started the year in the Grade II Elkhorn Stakes at Keeneland on April 10, 1992, where he withstood an early duel for the lead to win by a neck over Slew the Slewor.^[8] He then ran four more times in quick succession, finishing third in the Turf Classic Stakes at Churchill Downs, second in the Dixie Handicap at Pimlico, fifth in the Early Times Manhattan Handicap at Belmont and fourth in the New Hampshire Sweepstakes Handicap at Rockingham Park.^[2]

He was then given a break of nearly two months, returning on August 3 to finish second in an allowance race at Saratoga.^[2] He was next entered in the Bernard Baruch Handicap on August 12, where he was expected to race as an entry with his full brother Fourstardave. However, Fourstardave was scratched, leaving Fourstars Allstar the solo favorite in a field of six. He won by half a length over Lotus Pool in a time of 1:46.06 for 1+1⁄8 miles.^[9]

Bomze and O'Brien contemplated a return to Europe, perhaps for the Queen Elizabeth II Stakes at Ascot.^[9] However, they ultimately stayed in the United States, racing four more times without success. The best result was a fourth-place finish in the Keeneland Breeders' Cup Stakes.^[2]

1993: five-year-old season

Fourstars Allstar began his 1993 campaign in May when he ran fifth in the Fort Marcy Handicap at Aqueduct and third in the Red Bank Handicap at Monmouth Park, both races being won by the British import Adam Smith. On June 19, the horse made his second attempt to win the New Hampshire Sweepstakes Handicap at Rockingham. Ridden by José A. Santos he dead-heated for first place with Idle Son but was awarded the outright victory after the Idle Son was disqualified for causing interference in the straight.^[10][11]

After finishing sixth under top weight of 118 pounds in the Firecracker Handicap at Churchill Downs on July 4, Foourstars Allstar was off the track for seven weeks before returning in the Saratoga Breeders' Cup Handicap on August 28. Starting the 9.6/1 outsider in the six-runner field, he took the lead in the stretch and drew away to win by three lengths and a head from Lech and Cleone with the odds-on favorite Furiously in fourth place. After the race Leo O'Brien said "Well, everything went according to plan. I told (jockey José A. Santos) that the horse has one kick, and to wait until the eighth pole and he'll give you what he has".^[12]

The horse was stepped up to Grade I level for his two remaining starts as a five-year-old, starting with the Washington D.C. International Stakes on October 23 in which he made no impact and came home last of the eight runners. The Breeders' Cup Mile at Santa Anita Park two weeks later saw a return to form as Fourstars Allstar, starting a 74/1 outsider, was amongst the leaders from the start and kept on well in the straight to take third behind Lure and the French filly Ski Paradise, with Toussaud, Barathea, Bigstone, Paradise Creek, Flawlessly and Wolfhound finishing behind.^[13]

1994: six-year-old season

In 1996 Fourstars Allstar finished second to Paradise Creek in the Appleton Handicap at Gulfstream Park in January and was then off the course for almost four months before finishing fourth to Adam Smith in the Fort Marcy Handicap in May. Later that month he was matched against the 1993 Kentucky Derby winner Sea Hero in an allowance race at Belmont. He recorded his only win of the season as he "wore down" the Derby winner in the closing stage and won by a neck.^[14]

In his eight subsequent races in 1994, Fourstars Allstar failed to win but ran well in several major races. In June he finished third when odds-on favorite for the New Hampshire Sweepstakes Handicap and then produced one of his best performances when he was beaten a nose by Lure in the Caesars International Handicap at Atlantic City Race Course with Star of Cozzene in third. In late summer at Saratoga he finished third to A In Sociology in the Daryl's Joy Handicap and fourth in the West Point Handicap before moving to Belmont in September where he finished second in the Belmont Breeders' Cup Handicap and seventh in the Man o' War Stakes. In October, he finished eighth in the Keeneland Breeder's Cup Stakes and fifth in the Mohawk Handicap at Belmont.^[2]

1995: seven-year-old season

Fourstars Allstar began his sixth campaign on April 29, 1995 when he made his third attempt to win the Fort Marcy Handicap. Starting the 6.1/1 third choice in the eight-runner field he moved up on the outside to take the lead entering the straight and drew away to win by four lengths from Chief Master and A In Sociology with the favored Inside The Beltway back in sixth.^[15] He followed up a month later by winning an allowance race at Belmont by a neck from Bonus Award, to whom he was conceding ten pounds in weight. In July he ran second in the Poker Stakes at Belmont and the Daryl's Joy Stakes at Saratoga, beaten a head by Pride of Summer in the latter race.

On August 11 on rain-softened ground at Saratoga, Fourstars Allstar was one of seven horses to contest the 1995 edition of the Bernard Baruch Handicap, a race he had won as a four-year-old in 1992. Starting the 1.2/1 favorite under top weight of 120 pounds he raced wide for most of the way but took the lead in the closing stages and won by half a length and a head from Turk Passer and Compadre.^[16] Leo OBrien commented "I have to admit that I was very worried when it started to rain. This horse doesn't like the turf when it's soft".^[17]

In September Fourstars Allstar finished fifth in the Breeders' Cup Handicap at Belmont and third behind the subsequently disqualified Joker in the Cliff Hanger Handicap at Meadowlands. On October 14 he finished second to Pride of Summer in the Mohawk Handiacap before ending his track career with a run in the Breeders' Cup Mile at the same course two weeks later. After taking an early lead he turned into the straight in third place but faded in the closing stages to finish seventh behind Ridgewood Pearl.^[18]