Andy Murray squandered a match point in the second set and American Sam Querrey rallied on Sunday for a 5-7, 7-6, 6-3 victory over the British top seed in the final of the Los Angeles Open.

The 23-year-old Scotsman missed a golden chance for his first ATP title of the season and suffered his first loss in five career meetings with Querrey, who had never before taken a set off Murray.

“I’ve got to be happy getting to the final and having chances to win,” Murray said.

“I didn’t play my best tennis. Just tired.”

World number four Murray announced a split from coach Miles Maclagan last week. While he is looking at possible replacements, a final decision is not expected before the US Open.

Murray played in Los Angeles for the first time as a last-minute replacement for Serbian Novak Djokovic, who withdrew citing a need for more rest.

Hometown favourite Querrey won his fourth title of the season – only Rafael Nadal with five has more – and became the first back-to-back champion at the 700,000-dollar hardcourt event since Andre Agassi defended his crown in 2002.

“In the second and third sets I played great, some of the best tennis I’ve played,” Querrey said.

“That’s the highest-ranked guy I’ve ever beaten.”

Second seed Querrey double faulted to surrender the decisive break in the last game of the first set.

In the fifth game of the second set, Querrey blasted a forehand smash wide and netted a forehand to allow Murray to escape break points and hold serve.

Murray had a match point on Querrey’s serve in the 10th game but could not capitalise, sending a backhand wide, and the American held to level at 5-5.

“I wasn’t going to give it to Murray,” Querrey said.

“I was going to make him come up with a shot to beat me.”

In the tie-breaker, Querrey smacked a crosscourt forehand winner for a 4-1 lead and finished off Murray by scoring the last three points, the last on a forehand winner to finally take a set off Murray after nine prior failures.