The American, playing in only her second clay court match since her defeat to Garbine Muguruza in the final here two years ago, was staring down the barrel as the Australian broke to open set two but the level she exhibited after restoring parity – slapping winners at ease and moving with grace – suggests she could flout pre-tournament expectations and add a 24th Grand Slam title to her glittering resume.
Williams, however, will be grateful that she has been able to put herself in a position to reach the second week of a Grand Slam after it turned pear-shaped when Barty broke to start the second frame.
“I lost the first set and I thought I have to try harder and Serena came out,” she beamed courtside when quizzed about her emotions after surrendering the opening set.
Indeed, the American struggled to find her range during the opening exchanges, as Barty’s confidence grew with each convincing hold.
The Australian, who boasts a nasty backhand slice, was peppering Williams with her crafty cross-court forehands and she fashioned three break points in the sixth game of the match.
She needed no second invitation to capitalize on the opportunity, coaxing a wild forehand from the racket of her opponent to break. Consolidating the advantage, she held to 15 and it was evident that Williams was going through the motions.
The 22-year-old sealed the first set in half an hour of play and she rammed home her superiority to start set two.
She, again, constructed a triple break point opening – catching Williams off guard with a wicked slice as she approached the net – and had the advantage when the American netted a dismal forehand from inside the baseline.
However, the setback roused the three-time French Open champion, as she immediately broke back to screams of encouragement.
Suddenly the tide had shifted, as she carved out two break points in Barty’s next service game and broke with a backhand return winner. Her confidence was booming and she leveled the match as the clock elapsed the hour mark.
She was now restored to the all-empowering presence of two years, outlasting the Australian from the baseline and peppering the sidelines with groundstrokes that her opponent had no answer to.
The break of serve was inevitable and it arrived in game three as Barty double-faulted to bring up the crucial break point opportunity before nailing a forehand into the net.
Williams would not offer up another break point as she marched inexorably towards the finish line. Three match points were rung up on her serve and a gorgeous backhand winner down the line sealed her passage.