Britain's Dan Evans said his focus was "thrown out" by an unusual foot-fault ruling in his French Open first-round loss to Australia's Thanasi Kokkinakis.

While he said it was "not anywhere near the reason why" he lost, it did swing the momentum back to Kokkinakis.

"I lost all trust in where my feet were," the 20th seed said.

"But I was bottom drawer from start to finish and he was decent."

British men's number two Evans won for the first time at Roland Garros last year, but has now suffered a fifth loss in six first-round matches at the clay-court Grand Slam tournament.

"It was a difficult day, that's the bottom line, really. I was poor from start to finish," Evans, 33, said.

"[Thanasi] took advantage of it. He served well. It's frustrating really and that's about it."

Only two Britons - Jack Draper and Cameron Norrie - remain in the draw.

With Emma Raducanu injured, there are no British players in the women's singles after seven players lost in qualifying.

'It's a hard sport' - Evans frustrated at not cracking world top 20

Evans has long had a loveless relationship with the red dirt, but going into this year's French Open he said he was feeling "very prepared".

The clay-court swing started promisingly for the world number 25 with runs to the semi-finals in Marrakech and Barcelona.

However, he lost his opening matches in Monte Carlo, Madrid and Rome - the biggest tournaments going into Roland Garros - before heading to Paris.

In warm and lively conditions against wildcard Kokkinakis, Evans was unable to get on top of the Australian, who used his powerful forehand to force the Briton behind the baseline.

His serve came under pressure midway through the first set, with the Briton saving four break points in an 11-minute game to hold for 3-2 before his resistance ended when he next served.

The single break proved key in the opener but Evans reset at the start of the second and moved 4-1 ahead as he looked in a good position to level.

But Evans was annoyed by being penalised for the foot fault when he led 4-2 30-0 and the double fault swung momentum back to 108th-ranked Kokkinakis.

"It obviously threw me quite a bit because it just totally threw me and where I was then serving from," he said.

"My technique got thrown out. It's a very minor thing, but it became a pretty big thing in my head."

Evans lost the next four points as the Australian broke back in that game and then, after the 20th seed showed his anger by smashing a water bottle at the changeover, saw out the set by winning five games in a row.

With his exasperation increasingly evident, Evans dropped serve for 3-2 in the decider and belief seemed to be draining from him.

However, he did manage to rescue the break for 4-4 but was instantly broken back for 5-4 and Kokkinakis retained control to seal victory.

Afterwards Evans said it is "frustrating" not being able to crack the world's top 20 after spending most of the past three years in the top 30.

"I'm trying to do what I think is right to get there, but it's obviously not paying off," he said.

"It's hard. It's a hard sport. That's the bottom line."