Yousesf Msakni scored a hat-trick and dished out an assist as Tunisia claimed a valuable 4-1 victory away to Guinea to keep intact their lead at the top of their qualifying group and edge closer to a World Cup place on Saturday.
Naby Keita fired Guinea in front on 37 minutes but Tunisia roared back, with Msakni restoring parity on the stroke of halftime.
The 26-year-old beat the keeper at his near post with a superb low shot to make it 2-1 in the 75th minute before feeding the overlapping Amine Ben Amor to add the third six minutes from time.
Msakni completed his hat-trick in stoppage time with an easy tap in at the far post following a cross from Ali Maaloul.
Tunisia could have ensured a World Cup place with one match to spare had DR Congo stumbled against Libya in the other group match but the race will go down to the wire after Congo secured a 2-1 win.
DR Congo's Cedric Bakambu opened the scoring on 50 minutes but Elmutasem Al Musrati drew Libya level 19 minutes later. Wilfred Moke netted in the 74th minute to keep alive DR Congo's hopes.
Tunisia are on top of their group with 13 points, three ahead of DR Congo. Tunisia need only a draw against Libya in their final match next month to reach the World Cup for the first time since 2006.