Not since 2010, when TP Mazembe beat Esperance of Tunisia 5-0, has a club built such an emphatic first leg lead in the final.

Anthony Laffor and Tebogo Langerman made it 2-0 at half-time, with the third coming just after the break.

Sundowns are now firm favourites for the second leg in Alexandria where they will seek to win their first continental trophy and become only the second South African side to win Africa's top club prize.

Sundowns, watched by a capacity 40 000 crowd, were full value for the win, running Zamalek ragged on a hot afternoon.

But they did take their foot off the pedal in the closing stages where Zamalek gamely kept going in search of a consolation that might give them a chance in the return.

Sundowns scored first just past the half-hour mark when captain Hlompho Kekana played through a pin-point pass that saw Liberian international Laffor turn and then belt the ball with power.

Laffor has not been a regular for the team but emerged as coach Pitso Mosimane's 'joker' in the Champions League with vital contributions.

The second goal was a cross from fullback Langerman nine minutes later that caught Ahmed El Shenawy off his line and bounced in off the upright.

It had a touch of luck about it but was as much as the home team deserved.

Straight after the break Sundowns were on the attack again and Percy Tau's shot was headed goalwards when Islam Gamal helped steer it into his own net.

Zamalek had also conceded an own-goal when they lost to Sundowns at the same venue in the group phase.

Bassem Morsi came closest to pulling one back for the Egyptians in the last 20 minutes but his shot was blocked by Wayne Arendse, who was the only payer booked in the game and will miss the return leg.

Zamalek lost El Shenawy to a thigh injury and the reserve goalkeeper Mahmoud Genesh had to come in for the final stages, making one key stop to deny Tau on the final whistle.

Despite their 3-0 lead, Mosimane was cautious at the final whistle.

"We need to keep our feet on the ground, I've been in football for long.

"Zamalek scored four against Wydad in Alexandria in the semifinals. If we don't think they can get four against us, we'll be kidding ourselves. It's not over," warned the Sundowns coach.

If Sundowns lift the trophy next weekend, it will complete a remarkable turnaround in this competition for the South African club. They were knocked out in an early qualifying round by AS Vita Club, only to be brought back in when Vita Club were disqualified for fielding an ineligible player.

The second leg in Alexandria takes place on Sunday 23 October.