Mamelodi Sundowns claimed a vital 1-0 home win over Al Ahly in the first leg of their African Football League semi-final in Pretoria on Sunday.

A second half thunderbolt from Thapelo Maseko sealed victory for the South Africans, who largely bossed proceedings against the Egyptian giants at Loftus Versfeld Stadium.

The hosts dominated the early exchanges with Marcelo Allende pulling the strings in midfield, although clear chances were limited.

Maseko went closest for Sundowns when his effort was superbly denied by Mohamed El Shenawy just after the half hour mark.

But the lively winger finally found the breakthrough in the 52nd minute, firing an unstoppable long-range strike beyond El Shenawy.

Sundowns looked comfortable until the closing stages when Percy Tau appealed in vain for a penalty after going down under a challenge.

However, the single goal was enough for Sundowns to gain a slender advantage ahead of Wednesday's second leg in Cairo.

Coach Rhulani Mokwena will be satisfied with a performance that sets his side up nicely to progress to the inaugural AFL final.

But Al Ahly remain very much in the tie as they prepare to welcome Sundowns to their intimidating Cairo fortress.

The semi-final is finely poised.