Ukraine secured qualification for the 2020 European Championship with a 2-1 win at home to Portugal while Cristiano Ronaldo scored his 700th goal in his career.
Ukraine had a remarkable first-half performance with a 19-point lead from Group B with seven points, eight ahead of second-placed European champions Portugal, but Portugal have a game in hand.
Serbia are third on 10 points from six matches after a 2-1 win over Lithuania thanks to a double by Alexander Mitrovic.
Luxembourg have four points from six games, while Lithuania are bottom of the table with one point from seven.
Roman Yaremchok and Andrei Yarmolenko's goals gave Ukraine a 2-0 lead in the first half and Portugal were awarded a second-half penalty after Taras Stepanenko was given a red card for two yellow cards.
Ronaldo made it 2-0 in the 72nd minute, scoring his 95th goal and completing 700 goals with 450 goals for Real Madrid, 118 for Manchester United, 32 for Juventus and five for Sporting.