(CNN) -- Venus Williams was given a scare before edging past Lucie Safarova of the Czech Republic 6-2 4-6 6-2 at the Italian Open in Rome.
The Wimbledon champion appeared to be coasting to victory on the clay courts of the Foro Italico before meeting stiff resistance from her 22-year-old opponent.
Williams, who could meet sister and world number two Serena in the final after being placed in the opposite half of the draw, took the first set in just 28 minutes, mixing powerful serving with penetrating groundstrokes.
But Safarova broke Williams in the third game of second set and held out to level at one set all.
The decider hung on the third game as the American former world number one saved four break points.
She broke Safarova in the next game and again to close out a one hour 48 minute victory.
Williams is one of eight seeds to receive a first round bye, with another, Victoria Azarenka of Belarus having a far easier passage to the last 16.
Azarenka, who recently won the Miami Masters, was leading Ayumi Morita 6-0 when the Japanese player retired at the end of the first set.
Other seeds through in first round matches were No.9 Caroline Wozniacki of Denmark, 10th seed Agniesxka Radwanska of Poland and No.13 Alize Cornet of France.
The tournament, which comes hard on the heels of the men's Rome Masters, is an important warm-up for the French Open in Paris later this month.