Draper has only played two tournaments this year - winning three five-setters in a row to reach the Australian Open last 16 before finishing runner-up in Doha - as he has continued to manage a hip injury sustained in the off season.

The performance against Fonseca, whose matches are attracting large numbers of vocal Brazilian fans, was another example of his increasing maturity.

Initially below his best, Draper showed resilience and composure to subdue one of the fastest risers on the ATP Tour.

"I feel I did a really good job and I'm proud of the way I competed, the way I moved and what I did tactically," he said.

The buzz surrounding Fonseca, who became the fourth youngest man to win an ATP Tour title since 2000, led to hundreds arriving early to ensure they bagged a spot on the smaller fourth court at Indian Wells.

Fonseca's biggest weapon is a ferocious forehand and, while he regularly demonstrated his easy power from the baseline, there were also signs of his inexperience.

In moments where the world number 80 perhaps needed a little more subtlety, he continued to hit extremely aggressively and paid the price as Draper broke again in the ninth game.

The Briton continued to counter-punch well and took the opener on his second set point when Fonseca overeagerly pushed another forehand wide.

Saving four of five break points proved key for Draper, while Fonseca's 23 unforced errors outweighing nine winners was another key statistic.

Boosted by the lead, a more confident Draper vastly improved his first-serve percentage, dominated the rallies and moved sharply around the court.

The only blip in the second set was three successive double faults as he served for the match, but he recovered to clinch an impressive victory.

Draper knows a strong run in the Californian desert could push him into the world's top 10 for the first time in his career.

"I have still got a long way to go and build my tennis, fitness and mentality day in, day out," he added.

"I'm getting closer but I'm not a top-10 player until I get there."