Serena Williams and Kiki Bertens have played out several close matches in the past - and today wasn't an exception as the resurgent American needed nearly two hours of play to get past the hard-hitting Dutch, who ultimately fell in a tight 6-7, 5-7 second-round match at the BNP Paribas Open.
Williams will now face older sister Venus, whom she beat in the Australian Open decider at Melbourne Park a year ago.
There was conjecture that her withdrawal had been a family arrangement and Russia's Elena Dementieva said after her quarter-final loss to Venus that she believed the sisters' father and coach, Richard Williams, decided who would win their matches.
And Williams brought up three set points in the tie-break and she converted the third when Bertens sprayed a forehand well wide of the line.
"I'm really happy that I won this first-round match".
"But I have to play a seed regardless, sooner than later most times for the next couple of tournaments".
Still showing some rust from her long layoff, Serena hit just one ace and made 37 unforced errors to 32 for Bertens.
Serena, who lifted her 23rd Grand Slam title in Melbourne a year ago, was then already pregnant with daughter Alexis Olympia, who was born in September.
Serena Williams owns a 17-11 record against Venus Williams, having taken the most recent matchup in the final at Melbourne previous year.
Serena - a two-time champion at Indian Wells - was far from her free-flowing best against Bertens Saturday but she battled past the Dutchman after nearly two hours on court.
"Obviously I wish it was anybody else in the draw, literally anybody, but that's okay".
Venus and Serena have faced each other 28 times in their legendary careers and they are now meeting in Serena's first tournament back on the WTA Tour since she beat Venus 6-4, 6-4 in the 2017 Australian Open final. "It's just afterwards I don't like it as much".
Second seed Caroline Wozniacki had an easy time with qualifer Lara Arruabarrena 6-4, 6-1.
The start of the match had been delayed several minutes by light rain in a precursor of worse weather to come.
The fourth-seeded Elina Svitolina cruised to a 6-4 6-3 win over Mona Barthel.
In men's play earlier, world number four Grigor Dimitrov slumped to a shock 7-6 (7/4), 4-6, 6-3 defeat to Spain's Fernando Verdasco.