She was known for the "dance moves" she made while in the walking ring and post parade prior to her races,[3] and her taste for Guinness Stout contributed to her popularity.

[4] She was also known for her closing finishes, often spotting large leads to early front runners, then overtaking her opponents in the final strides.

"[3] On November 22, 2007, Zenyatta made her debut in a Maiden Special Weight at a distance of 6+1⁄2 furlongs over Hollywood Park's artificial track surface.

[14] On January 13, 2008, Zenyatta made her four-year-old debut in the Grade II El Encino Stakes at Santa Anita Park.

She broke last in the field of six but was only four lengths behind Tough Tiz's Sis, who set a moderate pace of 47.77 seconds for the first half mile.

Zenyatta swung wide turning into the stretch and steadily made up ground, drawing clear in the final strides to win by 1+3⁄4 lengths over Tough Tiz's Sis.

She broke poorly and was squeezed back but remained fairly closely bunched with the other four horses as Romance is Diane set "turtle-like fractions" of 24.74 seconds for the opening quarter mile and 48.19 for the half.

Zenyatta made an earlier move than usual and took the lead in mid-stretch, then held off Tough Tiz's Sis to win by half a length.

Her main rival in the four-horse field was Grade I winner Hystericalady, who came into the race off an eight-length win in the Molly Pitcher.

[26][27][28] On October 24, 2008, Zenyatta was sent off as the 1–2 favorite for the Breeders' Cup Ladies' Classic, held during the Oak Tree meeting at Santa Anita.

"[31] With a perfect record of seven wins in 2008, all at the Grade I or II level, Zenyatta was the easy winner of the Eclipse Award for Champion Older Female Horse.

Smith explained that he and Garrett Gomez, the jockey of Life is Sweet, "played some games" while battling for position on the turn.

"[40][41] On August 9, Zenyatta faced a field of six in the Clement L. Hirsch, now run as a stakes race under allowance weight conditions.

"[43] On October 10, Zenyatta again faced off with Life is Sweet, Lethal Heat and Cocoa Beach in the Lady's Secret Stakes at Oak Tree at Santa Anita.

This extended her winning streak to thirteen, tying her with Personal Ensign for the longest undefeated record at the elite level in North American racing history.

European-based horses had run one-two in the 2008 Classic and two Group One winners, Rip Van Winkle and Twice Over, were among the favorites in the 2009 version.

When the race finally began, Zenyatta was flat footed and trailed the field by 15+1⁄4 lengths after the first quarter, run by pacesetter Regal Ransom in a leisurely 24.16 seconds.

Zenyatta accelerated and began to rapidly gain ground, then pulled clear to win by a length over Gio Ponti.

[49][50] Track announcer Trevor Denman had kept an eye on the mare throughout the race, noting she had a lot of work to do at the top of the stretch.

"[49] The win set up a spirited debate over who should be Horse of the Year: Zenyatta or the equally brilliant three-year-old filly Rachel Alexandra.

[54] On December 22, Zenyatta was runner-up to tennis player Serena Williams for 2009 Associated Press Female Athlete of the Year.

[56] On December 26, opening day of the 75th year of the Santa Anita meet, Zenyatta jogged around the grandstand in what was then thought to be the final racetrack appearance of her career.

[58] On January 18, Zenyatta won her second Eclipse Award as American Champion Older Female Horse of the 2009 season.

[61] On the same day though, Rachel Alexandra, who had not run since September 2009, was defeated in the New Orleans Ladies Stakes at Fair Grounds Race Course.

[63][64] On June 13, 2010, Zenyatta won her 17th straight race in the Vanity Handicap at Hollywood Park by half a length under 129 pounds.

[67] However, he ultimately decided to keep her at home and entered her in the Lady's Secret on October 2 instead (the name change for the race to the Zenyatta Stakes was deferred for a year).

With three Grade I wins in 2010 and the head-to-head victory over Zenyatta, Blame's connections believed he deserved to be named Horse of the Year.

In her narrow defeat to Blame at Churchill Downs on a traditional dirt surface, she overcame many doubts over competition as the 2010 Classic was considered one of the deepest fields in its history with seven Grade I winners.

Other Grade I/Group One winners that she defeated included: Colonel John; Richard's Kid; Einstein; Tough Tiz's Sis; Cocoa Beach; Music Note; Life Is Sweet; Switch; Rip Van Winkle; Twice Over; Awesome Gem; Girolamo; Mine That Bird; Hystericalady; Romance Is Diane; Double Trouble; Santa Teresita; and Carriage Trail.

[107] She was featured in O[108] and W Magazine[109] and in a profile on 60 Minutes[110] in 2010 prior to her historic attempt at 20 consecutive victories in the 2010 Breeders Cup Classic.