Title-holders Mamelodi Sundowns of South Africa and record eight-time winners Al Ahly of Egypt were surprisingly held to goalless draws at home Saturday as matchday 1 of the CAF Champions League concluded.
Group stage debutants Saint George of Ethiopia forced a 0-0 stalemate with Sundowns at a wet and cold Lucas "Masterpieces" Moripe Stadium in a Pretoria township.
Zanaco of Zambia, another club appearing in the mini-league phase of the elite African club competition for the first time, held Ahly 0-0 at Borg El Arab Stadium near Alexandria.
Sundowns, who beat Zamalek of Egypt 3-1 on aggregate last year to win the Champions League for the first time, dominated play and squandered several good scoring chances.
The best fell to Sibusiso Vilakazi, signed after the African triumph, during the second half, but he blazed wide after a cross from Liberian Anthony Laffor created an opening.
Sundowns coach Pitso Mosimane said during the build-up to the match that he was concerned about fixture fatigue affecting his team, who have been playing twice virtually every week.
But a lack of flair rather than fitness proved their undoing against Saint George, who defended in depth and Ugandan goalkeeper Robert Odongkara made several fine saves.
Ahly wasted a great chance to snatch victory in stoppage time when Ivorian Souleymane Coulibaly failed to beat Zanaco goalkeeper Toaster Nsabata from close range.
The 22-year-old who was once on the books of Tottenham Hotspur controlled a cross only to hit the ball at the shot-stopper, who used his left leg to parry it.
Ahly, whose last Champions League title came in 2013, camped inside the Zanaco half as time ticked away and Moemen Zakareya fired a half-chance just wide.
The Champions League group phase expanded from eight clubs to 16 this season and increased prize money guarantees a mininum of $550,000 (505,000 euros), a $150,000 increase from last year.