Heather Watson loses to Carla Suarez Navarro at Indian Wells

Heather Watson intends to keep improving after her impressive run at Indian Wells ended with a frustrating loss to Spain's Carla Suarez Navarro in the last 16.

The British number one served for the first set and forced a decider, but went down 7-6 (7-5) 3-6 6-1.

Watson, 22, had beaten seventh seed Agnieszka Radwanska in round three.

"I need to learn what I need to do better next time, stay positive and keep improving," she said.

Suarez Navarro, ranked 30 places above Watson as the world number 13, will play third seed Simona Halep or 14th seed Karolina Pliskova in the last eight.

Despite the fourth-round defeat, Watson has still enjoyed one of the best weeks of her career and will collect £40,000 and 120 ranking points as she looks to surpass her career high of 38 in the world.

She told BBC Radio 5 live: "I had my chances but wasn't able to take them. I gave it my absolute best, everything I had, I just wasn't the better player."

Watson looked capable of pulling off another shock as she moved 5-3 ahead in the first set, with Suarez Navarro limping after receiving treatment on her foot.

The Brit then became the more tentative, however, failing to put away a short forehand as she served for the set, and Suarez Navarro reeled off three straight games to force a tie-break.

"The injury did throw me off a bit," Watson admitted.

The Spaniard's high, looping topspin began to draw errors from the Watson forehand and she converted her third set point when the Briton sent one wide.

A rasping forehand winner gave Watson a much-needed boost as she broke early in the second and she got the better of three breaks on her way to levelling at one set all.

The opening exchanges of the decider were tight, but Watson crumbled from 40-0 in game four, cracking her racquet on the court as she handed over the break of serve.

Suarez Navarro has made her best ever start to a year and the 26-year-old capitalised on her opportunity with another break as she eased through the closing games.

Elsewhere, Andy Murray and partner Thanasi Kokkinakis were knocked out of the doubles at the second round stage.

Britain's Murray and the Australian teenager had been handed a wild-card into the event but were beaten 6-1 6-4 by Serbia's Nenad Zimonjic and Marcin Matkowski of Poland.