When the tennis world last saw Serena Williams, she was struggling with a back injury at the Australian Open.  That injury contributed to a stunning fourth-round loss to Ana Ivanovic, who still played inspired tennis in knocking off the world No. 1.  On Monday, both women won their opening matches WTA Premier tournament in Dubai.

Williams had lost at the Australian Open two years ago to Ekaterina Makarova, her first Dubai opponent.  And Makarova had started 2014 in strong form, having reached the second week in Melbourne for the third straight year and won her first hard-court title in Pattaya City.  It was hardly surprising, then, that she extended the rusty world No. 1 to a first- set tiebreak.  Extended across 18 points, this tiebreak was the longest that Serena had played since Wimbledon in 2010 and her longest on a hard court since Miami in 2005.

Once she eked out the tiebreak, Williams cruised through a second-set bagel to avenge her loss at the 2012 Australian Open.  As one might expect from a player scraping off post- injury rust, she finished the match more impressively than she started it.  Still, she will want to improve her serve for the rounds ahead.  Normally the best server in the WTA, Serena compensated for eight aces with seven double faults.  Her first-serve percentage hovered below 60%, while she did not dominate behind that first serve as formidably as she usually does.  Her modest performance in this area may have stemmed from lingering concern over her back.  Once Serena recovers full confidence in her health, her dominant serving should return.

If the world No. 1 found her victory arduous, the woman who defeated her in Melbourne battled much harder to advance.  Former No. 1 Ana Ivanovic had rallied twice from losing the first set at the Australian Open, including her sensational upset of Serena.  She pulled off the same feat in the first round of Dubai, dropping the first set to world No.  8 Angelique Kerber before surging back to claim the match in a third-set tiebreak. 

Not always resilient under pressure, Ivanovic found the same courage that carried her to an Australian Open quarterfinal in upsetting last week's Doha finalist.  The Serb had slumped to an early loss in Doha, not the way that she wanted to consolidate her January breakthroughs.  (Before the Australian Open, she had won a small title in Auckland by defeating long-time nemesis Venus Williams.)  Ivanovic's victory today extended her record against Kerber to 4-2, but she had lost both of their hard-court meetings last season.  This fiercely contested clash thus marked yet another sign that she might have turned a new leaf in 2013. 

Another former No. 1 hoping to turn a new leaf, Caroline Wozniacki, recorded her first victory under new coach Michael Mortensen.  Like Ivanovic, Wozniacki rallied from losing the first set to a German opponent, Sabine Lisicki.  But the news was not all grim for Germans on Monday in Dubai.  Qualifier Annika Beck notched her second top-20 win in two days over Samantha Stosur, having defeated Eugenie Bouchard in the final round of qualifying. 

There will be no Doha-Dubai double in February after Doha champion Simona Halep retired early in the second set against Alize Cornet.  Halep cited a right ankle injury, from which she should have plenty of time to recover before the Premier Mandatory events at Indian Wells and Miami in March.