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Lesson No. 1 for Novak Djokovic's opponents in the first two rounds of the Australian Open has to be: Don't break the Serb's serve. Both Paolo Lorenzi and Santiago Giraldo scored early breaks against Djokovic and were then dusted. The No. 1-seed reeled off 17 straight games against Lorenzi and eight straight today against Giraldo, finishing off the heavy underdog in a 6-3, 6-2, 6-1 second-round rout.

Djokovic invoked the Three D's in stopping Giraldo's attempt to become the second Columbian player in as many days to score a big upset: Great depth, sterling defense, and a diverse repertoire of shots. Giraldo's countryman, Alejandro Falla, knocked off Mardy Fish yesterday, and Giraldo did not appear intimidated early in today's match as he broke Djokovic's serve at 2-2 in the first set. But Djokovic broke back at love and Giraldo, the No. 56-ranked player, didn't win another game until Djokovic was up 4-0 in the second set.

Djokovic put non-stop pressure on Giraldo and sent him scurrying all around the Rod Laver Arena court in pursuit of crafty angle shots, booming down-the-line blasts, and soft backhand drop shots. The Serb won points with aces, searing backhand drives, inside-out forehands, volleys, and once with a forehand topspin lob. Djokovic hit nine aces to only two double faults, won 81 percent of the points on his first serve, and 66 percent of points on his second serve. The sound of Djokovic's Adidas shoes screeching and skidding on the hard court surface gave an audible account of how quickly he goes from defense to offense.

The Serb looks like he is already in a high-level groove as he gets ready to take on Nicolas Mahut in the third round. Djokovic beat Mahut in the only other time they played, in 2006 on the hard courts of Metz. Mahut will give Djokovic a new look than both Giraldo and Lorenzi by playing a good amount of serve and volley. If the defending champ gets by that, Djokovic could face another net rusher in Round of 16 in young gun Milos Raonic, who awaits a match-up with either Andy Roddick or Lleyton Hewitt.

—Dan Markowitz

Dan Markowitz is writing a book on the upcoming 2012 season entitled "Chasing the GOAT: Roger, Rafa & Nole."