Jelena Jankovic received an umpire's warning and a big scare before she won a tough three-setter against Virginie Razzano.
Umpire's warning for Serbian, Serena faces semi-final rematch.
Jelena Jankovic received an umpire's warning and a big scare before she won a tough three-setter against Virginie Razzano, but there were no such problems for defending champion Serena Williams.
Serbian star Jankovic endured a second tough match already in just the third round of the tournament before she eventually beat French number 30 seed Razzano 6-2 4-6 6-1.
Third seed Jankovic broke her opponent three times in the first set, but that only inspired Razzano to break Jankovic twice on her way to levelling the match.
Jankovic got back into her stride and powered her way through the final, but the two-hour battle - played in the hottest time of what has been the warmest day of the Open so far - followed on from Jankovic's epic first-round win over Austria's Tamira Paszek, which she clinched 12-10 in the third set.
Tired
"I wish I could have finished that match in two sets," said Jankovic.
"I got very tired and you probably could have seen that during the match with my attitude because my head was down and I just kind of dragging myself around the court.
"Playing in the sun, in the heat, it's not a nice feeling and sometimes you feel dizzy"
Jankovic also had to deal with a warning from the umpire for receiving coaching from her mother in the stands - a charge she emphatically denied post-match.
"I think that was wrong because my mum is just supporting over there in my box," she said.
"She just said 'Come on' in Serbian and I don't know what else she said. It was not right because she (the umpire) doesn't understand what my mum told me in Serbian, she didn't coach me so I don't think that's a coaching violation.
"I have never received something like that before."
Serena in stride
As Jankovic struggled, defending champion Serena Williams stayed on course for a fourth success at Melbourne Park with a commanding 6-3 6-4 win over Victoria Azarenka.
The American whistled down 14 aces in the match which took her 72 minutes to win against the Belarussian.
Number seven seed Williams now faces Czech teenager Nicole Vaidisova in the fourth round, in a rematch of last year's semi-final.
Vaidisova beat Japan's Ai Sugiyama 6-3 6-4 to set-up a return against Williams, and the young Czech is already formulating a gameplan.
"I think I will move her around more than I did last year," Vaidisova said.
"It's definitely going to be a big test because she's a hard hitter and I have to have everything, my movement, my focus, my game, at my A level."
