Djokovic, No. 2 in the world rankings, ran his Australian Open winning streak to 25 matches and his overall run to 28 match wins with a 6-3, 6-0, 6-2 win over No. 15th-seeded Fabio Fognini in a brisk 92 minutes.
Djokovic was in control throughout the match versus Fognini, against whom Djokovic is now 7-0. He dropped only 10 points on serve and didn't allow Fognini a break chance. He also won 51 percent of the points off Fognini's serve, recording six breaks.
Djokovic has now reached the quarterfinals of 19 consecutive Grand Slam tournaments. He's been in the quarters the last seven years in Melbourne, where he won in 2008 and 2011-13. An Australian Open win in 2014 would give him an Open Era record five titles.
Ferrer was a 6-7 (5-7), 7-5, 6-2, 6-1 winner over Florian Mayer after winning about 70 percent of the points after the first set. He ended up with nine breaks, with three in each the second and fourth sets.
Berdych, making a fourth consecutive trip to the Australian Open quarterfinals, ousted 19th-seeded Kevin Anderson 6-2, 6-2, 6-3. Berdych didn't face a break point and committed only 17 unforced errors. He won more than three-quarters of the points on serve.
Wawrinka wrapped up Sunday's play with a 6-3, 7-6 (7-3), 7-6 (7-5) win over 17th-seeded Tommy Robredo, beating Robredo for only the second time in eight meetings. Wawrinka had a clear edge in points won -- 118-96 -- but had trouble completely shaking Robredo until Robredo sent a final shot into the net.
He won a very healthy 73 percent of the point on serve and lost his serve only once, that coming in the second set.
That put Wawrinka into the quarterfinals against Djokovic. Those two played an epic semifinal last year at the Australian Open with Djokovic prevailing 12-10 in the fifth set. Djokovic was 4-0 versus Wawrinka in 2013 and improved his head-to-had series to 15-2. Wawrinka last beat Djokovic in 2006, 14 matches ago.
Ferrer is 7-4 versus Berdych but they've never played each other in a Grand Slam event.