Serena Williams battled her way into the third round of the China Open with an unconvincing 6-4 7-5 victory over Francesca Schiavone.
Williams, the world No 1, appeared agitated at times, regularly berating herself over lost points and this was a much tougher battle than when the pair played in the first round of the US Open in August.
Williams won that match 6-0 6-1, losing just 23 points in the process.
The 17-time Grand Slam singles winner showed just rare moments of her trademark power-play in Beijing, only taking the first set after Schiavone double-faulted on set-point.
Schiavone, Italy's first Grand Slam winner at Roland Garros in 2010 and the current world No 50, forced Williams to become more aggressive in the second set after breaking her serve in the opening game.
As the competition intensified, both players' tempers threatened to boil over, with Williams shouting and Schiavone smashing balls into the barriers at the side of the court.
Williams eventually calmed down and after completing her victory said: "I was able to save some energy, so I started walking slower and taking my time more. When I did that, I actually won three or four games in a row."
The 32-year-old and her sister Venus suffered a shock first-round exit in the doubles competition on Monday and Venus also departed the singles event on Tuesday after being thrashed by Germany's Sabine Lisicki.
Lisicki dominated her veteran opponent and reeled off 29 winners during an emphatic 6-1 6-2 win which took just 53 minutes.
There were also wins for seeds Caroline Wozniacki, Roberta Vinci and Carla Suarez-Navarro, only Vinci requiring three sets to get past home player Zhang Shuai.
American Sloane Stephens won the battle of two of the game's most exciting young talents as she prevailed in a tight final set to beat Canada's Eugenie Bouchard 6-1 1-6 6-4, while Maria Kirilenko beat Urszula Radwanska 6-4 6-4.