Third seed Rafa Nadal battled through illness and poor timing on his groundstrokes to lurch into the third round of the Australian Open with a 6-2, 3-6, 6-7, 6-3, 7-5 victory over American qualifier Tim Smyzcek.
Nadal appeared to be affected by something in the second set as he sweated profusely and took his time between changeovers before calling for the doctor early in the third set with television microphones picking up he had an upset stomach.
Earlier, second-seed Roger Federer survived a first set scare before he ramped up his performance and advanced safely to the third round with a 3-6, 6-3, 6-2, 6-2 victory over Italian journeyman Simone Bolelli.
Federer initially looked out of sorts against the 29-year-old Italian, who was perhaps feeding off the energy Alexandra Panova generated in almost beating women's second seed Maria Sharapova immediately before their match on Rod Laver Arena.
Andy Murray trounced Marinko Matosevic 6-1, 6-3, 6-2 to also reach the third round but insisted there was no edge to the match after the Australian's criticism of his decision to hire Amelie Mauresmo as coach.
A merciless Murray wrapped up the match at Margaret Court Arena in a quick-fire 102 minutes, needing only 21 to seal the first set in which his opponent won only eight points.
Other results (selected):
10-Grigor Dimitrov (Bulgaria) beat Lukas Lacko (Slovakia) 6-3 6-7(10) 6-3 6-3
14-Kevin Anderson (South Africa) beat Ricardas Berankis (Lithuania) 6-2 6-2 7-6(3)
24-Richard Gasquet (France) beat James Duckworth (Australia) 6-2 6-3 7-5
Marcos Baghdatis (Cyprus) beat 20-David Goffin (Belgium) 6-1 6-4 4-6 6-0
Viktor Troicki (Serbia) beat 26-Leonardo Mayer (Argentina) 6-4 4-6 6-4 6-0
7-Tomas Berdych (Czech Republic) beat Jurgen Melzer (Austria) 7-6(0) 6-2 6-2