Serena Williams say she has “a long way to go” on her comeback after the birth of her child following defeat by sister Venus in round three at Indian Wells.

The former world number one hit four aces but had her serve broken four times in a 6-3 6-4 loss in California.

“It wasn’t easy, obviously,” said Serena, who was in her first event since beating Venus in the 2017 Australian Open final.

Venus moves on to the round of 16 where she will face Anastasija Sevastova.

Latvian Sevastova beat German Julia Goerges in straight sets 6-3 6-3.

It was the 29th meeting between the Williams sisters – Serena now leads 17-12 – and it lasted 87 minutes in front of a main stadium crowd of more than 10,000 fans, including current world number one Simona Halep.

Serena, 36, saved a match point against her elder sister but hit a forehand long to end the contest.

“It was good to play and try to get in the rhythm and get into the swing again,” added Serena, who gave both just over six months ago.

“I can’t really replicate the situation no matter how much I do in practice. I make those shots 10 times out of 10 in practice.

“It’s just the nerves, the anticipation you feel naturally. It’s a little bit of everything that comes in a match that just doesn’t normally happen.

“It’s good that I don’t have to say that this is the best tennis I have ever played and I lost. My room for improvement is incredible,” added Serena.

“So I have just got to keep saying at each tournament that my goal is just to be better than the last. I don’t want to go backwards.”

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• ‘Doctors aren’t listening – Williams on ‘heartbreaking’ childbirth statistics
• Bumps, boobs and bouncing back – an athlete’s path through pregnancy
• Live scores, schedule and results

Serena was already pregnant with daughter Alexis Olympia, who was born on 1 September, when she beat Venus 6-4 6-4 in Melbourne at the start of 2017.

However, she revealed in February that she “almost died” after giving birth and was bedridden for six weeks.

Analysis

Russell Fuller, BBC tennis correspondent

This was a match that even the world number one wanted to watch.

Simona Halep, who is due on court at 11:00 local time on Tuesday for the first match of the day, joined more than 10,000 fans to watch the 29th meeting between the pair.

Serena may have won eight of their previous nine matches, but it was apparent from fairly early on that Venus was the stronger and steadier this time around.

Venus’ double fault count accelerated as Serena threatened to stage a late fightback, but the number eight seed was playing at a level her sister can’t yet match.

But this was still a hugely encouraging week for Serena. She heads to the Miami Open with three matches under her belt, and still with plenty of time on her side until the summer’s run of three Grand Slams begin at Roland Garros in late May.

World number two Caroline Wozniacki reached the fourth round of the BNP Paribas Open at Indian Wells with victory over Aliaksandra Sasnovich.

Wozniacki, who won her first Grand Slam at this year’s Australian Open, came through 6-4 2-6 6-3.

The 27-year-old Dane needs to win the tournament and hope that top seed Simona Halep fails to reach the final to regain the world number one ranking.

Wozniacki faces Daria Kasatkina, who beat US Open champion Sloane Stephens.

American Stephens has been struggling since breaking through for last year’s major win, and has failed to advance past a quarter-final this year. She was beaten 6-4 6-3 by Russian 20th seed Kasatkina.

Serena Williams saw her comeback ended 6-3 6-4 by sister Venus.

Caroline Garcia also progressed in straight sets against Daria Gavrilova as the French seventh seed beat the Australian 7-5 6-4 in just under two hours.

Former world number one Angelique Kerber beat Russia’s Elena Vesnina 7-5 6-2 to go through, while USA’s Danielle Collins beat Russian Sofia Zhuk 6-4 6-4.

Fourth seed Elina Svitolina fell to Carla Suarez Navarro 7-5 6-3.

Andy Murray could make his return from hip surgery at one of two new indoor events in Britain later this spring.

Murray said after his operation that he hoped to return “around the grass court season, or maybe slightly before”.

The Scot, 30, is unlikely to want to return on physically demanding clay, which precedes the grass court season, and his options elsewhere are limited.

But the Lawn Tennis Association (LTA) has announced two new indoor hard court events in Glasgow and Loughborough.

Both will be staged on the ATP Challenger Tour, the level below the ATP World Tour, with a prize fund of $100,000 (£72,000)

The first will take place at the Scotstoun Tennis Centre in Glasgow between 28 April and 6 May. The second is scheduled for Loughborough University’s Tennis Centre from 19-27 May.

The LTA says the tournaments will provide “quality playing opportunities for British players” in the run up to Wimbledon, but it seems very unlikely they would have been established at short notice had it not been for Murray’s impending return. The LTA has not yet committed to staging the tournaments in future years.

Murray’s management team and the LTA are understood to have been involved in discussions about the creation of these events, even though there can be no guarantee the former world number one will be fit for either. The double Wimbledon champion has said consistently he will not come back until absolutely ready.

He has not played a competitive match since Wimbledon last year and pulled out of this season’s Australian Open with injury before undergoing surgery on 8 January.

He is due to return to the practice court in the next couple of weeks and is planning to head overseas, to an as yet undecided destination, for some warm weather training in April.

A return to competitive tennis on home soil in Glasgow at the end of April would represent a swift recovery from his surgery, but should not yet be ruled out.

Were Murray to return in Loughborough three weeks later, then he would only have one more week to wait for the start of the grass court season, in south-west London.

The Surbiton Trophy is another event on the Challenger Tour – a level Murray has not played at since October 2005.

World number one Roger Federer reached the last 16 of the BNP Paribas Open at Indian Wells with a comfortable victory over Serbia’s Filip Krajinovic.

Federer, the defending champion and five-time winner, needed just 58 minutes to wrap up a 6-2 6-1 victory.

The 36-year-old Swiss will face Frenchman Jeremy Chardy next after he beat Adrian Mannarino 7-5 4-6 6-1.

Federer, a 20-time Grand Slam champion, has already won the Australian Open and Rotterdam Open this year.

Serena Williams will play her sister Venus at Indian Wells, 17 years after a scheduled meeting at the tournament sparked a 14-year boycott.

The 29th professional contest between the pair will take place in the first match of Monday’s night session.

Venus has only beaten Serena once since 2009, but the younger sister has just returned after becoming a mother.

The two were due to meet in the semi-final of 2001, but Venus Williams withdrew five minutes before the match.

She cited tendinitis in her knee as her reason for pulling out of the tournament.

And when Venus, accompanied by her father Richard, took her seat to watch her sister play Kim Clijsters in the final two days later, the atmosphere turned sour.

There was booing and jeering, and some of Serena’s unforced errors where cheered as she claimed the title in three sets.

“I literally didn’t even think about it,” Serena replied, when asked whether she was happy the match would finally get to take place.

“That’s, you know, totally gone out of my mind. First of all, 17 years ago seems like forever ago.”

Williams has said she spent “hours crying in the Indian Wells locker room” after the final, and would not return to the tournament until 2015.

In an essay for Time magazine just before her return, she made it clear she feels much of the vitriol was racist in nature.

“The false allegations – that our matches were fixed – hurt, cut and ripped into us deeply. The undercurrent of racism was painful, confusing and unfair,” she wrote.

Venus ended her boycott a year later, and now they are set to meet for a place in the last 16.

Venus, seeded eighth, reached the Wimbledon final, the US Open semi-finals and the championship match of the WTA Finals while Serena was away from the tour.

But Serena says she did not watch a single point on the grounds she gets too nervous.

“I never won a match sitting down,” she explains.

“So if she makes a mistake, a little bit of me dies. So, yeah, I didn’t watch any.”