Top seed and two-time defending champion Novak Djokovic and fourth seed David Ferrer were among Wednesday's second-round winners at the Australian Open.

The world No. 1 Djokovic dismantled helpless American Ryan Harrison 6-1, 6-2, 6-3 in 1 1/2 hours at Melbourne Park's Rod Laver Arena.

"I tried to focus from the start," Djokovic said. "Obviously, I knew he had nothing to lose, he's going to come out and hit big serves. Pity for him, I don't think he played his best."

The three-time overall Aussie Open champion Djokovic is trying to become the first three-peat champion in the Open Era at this Grand Slam event. He outlasted Rafael Nadal in last year's final, the longest Grand Slam final in history.

The super Serb will meet Czech veteran Radek Stepanek on Friday.

Ferrer also beat an American on Day 3, as the gritty Spaniard handled Tim Smyczek 6-0, 7-5, 4-6, 6-3. Ferrer is fresh off his title in Auckland last week and will tangle with flashy Cypriot Marcos Baghdatis in the third round.

In some other top-10 action, fifth-seeded former Wimbledon runner-up Tomas Berdych whipped Frenchman Guillaume Rufin 6-2, 6-2, 6-4, eighth-seeded Serb Janko Tipsarevic outlasted Slovak Lukas Lacko 6-3, 6-4, 3-6, 4-6, 7-5 in just under four hours, and 10th-seeded Nicolas Almagro cruised past fellow Spaniard Daniel Gimeno-Traver 6-4, 6-1, 6-2.

Up next for Berdych will be Austrian left-hander Jurgen Melzer.

In other play involving top-20 seeds, No. 15 Stan Wawrinka topped German Tobias Kamke 6-3, 7-6 (7-4), retired, No. 16 rising Japanese Kei Nishikori bested Argentine Carlos Berlocq 7-6 (7-4), 6-4, 6-1, and No. 20 Sam Querrey was trailing fellow American Brian Baker 6-7 (2-7), 1-1 when Baker retired from their encounter early in the second set because of a bad knee injury. Querrey will meet Wawrinka in the round of 32.

The snake-bitten Baker left the court on a wheelchair after suffering a torn meniscus in the knee, which will keep him sidelined for four months.

"He said he kind of just felt his knee almost buckle and kind of heard like a pop or a snap," Querrey said. "He didn't know if it was bones or a tear, but he couldn't straighten it, couldn't walk. I feel awful for him."

Baker enjoyed a big comeback last year in a career that has been abbreviated thanks to multiple surgeries, including three on his hips, one to repair a sports hernia and Tommy John surgery on his elbow.

Meanwhile, 22nd-seeded Fernando Verdasco whipped Belgian Xavier Malisse 6-1, 6-3, 6-2; Evgeny Donskoy upended 23rd-seeded fellow Russian Mikhail Youzhny 3-6, 7-6 (7-4), 6-2, 3-6, 6-3; 24th-seeded hot-headed Pole Jerzy Janowicz snuck past Indian Somdev Devvarman 6-7 (10-12), 3-6, 6-1, 6-0, 7-5; the 26th- seeded Melzer edged out Spaniard Roberto Bautista Agut 6-7 (4-7), 6-3, 6-7 (3-7), 6-3, 6-2; the 28th-seeded former Aussie Open runner-up Baghdatis overcame Japanese Tatsuma Ito 3-6, 6-3, 6-2, 6-2; the 31st-seeed Czech Davis Cup hero Stepanek tackled Spanish lefty Feliciano Lopez 6-2, 6-2, 6-4; and 32nd-seeded Julien Benneteau beat fellow Frenchman Edouard Roger-Vasselin 4-6, 7-5, 7-6 (7-5), 7-6 (7-5).

The rising Janowicz suffered a meltdown of sorts in his second-round win.

On set point in the first-set tiebreak, the towering Pole appeared to have won the set when Devvarman landed a forehand wide that was called in. With no replay out on Court 8, Janowicz appealed to the chair umpire for an overrule to no avail.

That's when Janowicz lost it.

"How many times? How many times? How many? I'm begging you!" he screamed before spitting on the line. "It's no fun to play like this!"

After Janowicz lost the tiebreak, he lobbed a ball softly in the umpire's direction, hit the umpire's chair with his racquet and threw a water bottle across the court to earn a code violation.

"Actually, I went nuts. I calmed down little bit later on. Sometimes I have problem to control my emotions, but I'm trying to work on this."

One other second-round result saw South African Kevin Anderson, a runner-up in Sydney last week, erase Russian Andrey Kuznetsov 6-1, 7-5, 6-4.

The second round is scheduled to conclude here on Thursday, including matches for second-seeded former world No. 1 Roger Federer and third-seeded two-time Aussie Open finalist Andy Murray.

The 17-time Grand Slam champion Federer, a four-time Aussie champ and the reigning Wimbledon titlist, will face former world No. 3 Russian Nikolay Davydenko, while the reigning U.S. Open and Olympic champion Murray will be opposed by Portuguese Joao Sousa.

Also slated for action on Day 4 are sixth-seeded former U.S. Open champion Juan Martin del Potro, seventh-seeded 2008 Aussie runner-up Jo-Wilfried Tsonga, ninth-seeded Richard Gasquet, and 13th-seeded Canadian slugger Milos Raonic.