The former Wimbledon finalist has slipped to 114th in the world rankings following an indifferent run of form over the last two years.

She proved untroubled in her first match of the Women's Tennis Association event, as she beat American wildcard Allie Kiich 6-2, 6-2.

Sabine Lisicki, who made the Wimbledon final a year before Bouchard, was forced to retire from her qualifying match due to injury.

She trailed 4-6, 6-3, 3-1 to fellow German Andrea Petkovic before having to pull out of the contest.

Italy's Roberta Vinci, runner-up at the US Open in 2015, came from a set down to reach the second round of qualifying.

Vinci battled back to beat the United States' Sachia Vickery 5-7, 6-1, 6-2.

Her countrywoman Sara Errani, who served a two-month doping ban last year after allegedly ingesting her mother's breast cancer medication inadvertently, suffered defeat.

The former French Open finalist was beaten 6-4, 5-7, 7-6 by the Czech Republic's Tereza Martincova.

In men's qualifying, Australia's John Millman emerged as a 6-3, 7-6 winner against Norway's Casper Ruud.

His compatriot Thanasi Kokkinakis, a wildcard entrant, claimed a 6-2, 6-3 win over Brazil's Thiago Monteiro.

Qualification is set to continue tomorrow.

Switzerland's Roger Federer is the defending men's champion at the tournament, while Britain's Johanna Konta won the women’s title last year.

Both players will be hoping to retain their titles, with the main draw beginning on Wednesday (March 21).