Serena Williams had a tough win over the woman she's predicting will one day top the rankings as she set up a semi-final match at the Brisbane International against current No. 1 Victoria Azarenka.
The reigning Wimbledon, US Open and Olympic champion showed plenty of emotion on key points in a heavy-hitting duel with Fed Cup teammate Sloane Stephens on Thursday before winning 6-4, 6-3.
Williams converted both of her break points and fended off one break chance against her in each set, later saying Stephens had the potential to be "the best in the world one day.''
Stephens was hitting the ball hard and cleanly, and got the better of some powerful rallies, but lacked experience in the two key moments - giving up a set point after wasting a game point on her own serve in the first and then dropping serve in the eighth game of the second set.
The 19-year-old Stephens appeared to suggest in the second set that some of the animated fist pumps and "Come On'' calls coming from the other side were disrespectful, but later said she was just joking with her coach and accepted the warm praise from Williams, her childhood idol.
"To have someone like that who I think is one of the greatest players to ever play the game say that about you is really nice,'' Stephens said.
"I lost to the best player in the world today, so, you know, it's good.''
Made to work
Olympic and US Open champion Andy Murray was pushed further than he expected before winning his opening match 6-1, 5-7, 6-3 against Australian qualifier John Millman, who finished last year ranked No. 228.
The third-ranked Murray, the defending Brisbane champion, clutched at his stomach after missing a forehand in the third game of the second set and later had to save four set points before Millman evened the match at one set apiece.
Murray recovered from his lapse, got the only break in the deciding third set and finished off by holding serve at love. He'll meet Denis Istomin of Uzbekistan, a 7-5, 7-5 winner over former No. 1 Lleyton Hewitt, in the quarterfinals.
In the other men's second-round matches, Grigor Dimitrov of Bulgaria upset No. 2-seeded Milos Raonic of Canada 6-3, 6-4 and No. 7 Jurgen Melzer of Austria had a 6-5, 7-6 (4) win over David Goffin of Belgium.
The women's semi-finals are set for Friday, with Williams getting the least recovery time.
She seemed to have trouble with her right calf muscle midway through the second set against Stephens, knocking her lower leg three times with her racket before she served at 40-0 in the fifth game, but later said she didn't have any injury concerns.
"I definitely want to thank (Stephens) for giving me such a great match, because I'm going up against another good player, great player tomorrow, so I have to make sure I'm ready,'' she said.
Williams has an 11-1 record against Azarenka and was 5-0 against the 23-year-old Belarussian in 2012, including the US Open final.
Azarenka started the year on a run, winning the Sydney International and the Australian Open - her first major - and gaining the No. 1 ranking during a 26-match winning streak.
But after a first-round exit in the French Open, Williams finished 2012 as the most dominant woman on tour. She has won 34 of her last 35 matches, including titles at Wimbledon, the London Olympics, the US Open and the WTA Championships.
With the Australian Open starting on January 14, and neither Azarenka nor Williams playing another tournament before then, Friday's semi-final shapes up as a classic.
"I'm going up against the world's greatest tomorrow. She had a fabulous (last) year,'' Williams said of Azarenka.
"I feel like I have nothing to lose. She's playing so well, she won I think in 20 minutes today. I have a lot of work to do tomorrow.''
That was a slight exaggeration. Azarenka took 68 minutes to win her quarterfinal match. And she was looking forward to a chance to beat Williams, a 15-time major winner, before the first Grand Slam event of 2013.
"Well, it's a tough match, there is no question about it,'' Azarenka said.
"It's going to be a great test for the Australian Open.''
Azarenka and Williams are the only two seeded players still in contention in Brisbane after No. 36-ranked Anastasia Pavlyuchenkova of Russia beat No. 4 Angelique Kerber of Germany 7-6 (3), 7-6 (3) in the first of the quarterfinals, her second win over a top 10 player this week after eliminating 2011 Wimbledon champion Petra Kvitova in the first round.
Pavlyuchenkova will next play Lesia Tsurenko of Ukraine, the lucky loser from qualifying who got into the main draw when No. 2-ranked Maria Sharapova withdrew due to a sore right collarbone. Tsurenko had a 6-3, 6-4 win over Daniela Hantuchova of Slovakia.