Ukraine are currently top of the section with 16 points - five points clear of second-placed Portugal, who have a game in hand as the race for first position hots up in the latter stages of the campaign.
Since legendary forward Andriy Shevchenko took charge of Ukraine in the middle of 2016, the European nation have been in impressive form. Indeed, they have won 17 of their 30 fixtures under their current head coach - suffering just five defeats in the process.
The Main Team have hardly missed a beat during this qualification process, meanwhile, with a total of 16 points from six matches leaving them top of Group B. They have recorded five wins and one draw, in addition to scoring 13 times and conceding just once during an impressive campaign.
Shevchenko's side actually opened the section with a goalless draw in Portugal before embarking on a five-match winning run; they have beaten Luxembourg and Lithuania twice in their last five games, in addition to recording a thumping 5-0 home victory over Serbia towards the start of June.
Since becoming independent, Ukraine have failed to make it out of the group stages at a European Championships, losing all three of their games at the finals of Euro 2016. They have not actually been present at a World Cup since 2006, meanwhile, but they do appear to be heading in the right direction.
Indeed, a win over Portugal in Kiev would see them guarantee first position in the group and a spot at Euro 2020 ahead of their final match away to Serbia on November 17.
Despite winning their last three matches in the group, Portugal are playing catch-up at this stage of their campaign. Back-to-back draws against Ukraine and Serbia in their first two matches could come back to haunt them, although they will fancy their chances of picking up a positive result on Monday night.
Since the home draw with Serbia on March 25, Portugal have won in Serbia and Lithuania, in addition to beating Luxembourg on home soil last time out. Bernardo Silva, Cristiano Ronaldo and Goncalo Guedes scored the goals in Friday's match, which proved to be a comfortable 90 minutes for the UEFA Nations League winners.
Portugal will welcome Lithuania and travel to Luxembourg in their two games after this one, which is an indication of the importance of Monday's clash. Ronaldo & Co. will fancy their chances of recording a win, but Ukraine have shown themselves to be a very dangerous team during this qualification campaign.
It is difficult to write off the Iberian nation, however, due to the presence of a certain Ronaldo, who has now scored 94 times in 161 caps. They are, of course, also the holders of the European Championships having triumphed at Euro 2016 to lift the trophy for the first time.
There are perhaps teams better equipped to challenge for next year's crown, although the likes of Joao Felix, Ruben Dias and Ruben Neves suggest that there is a very bright future for A Selecao das Quinas.
Ukraine form: DWWWWW
Portugal form: DDWWW
Ukraine boss Shevchenko has no fresh injury concerns from the team that started against Lithuania on Friday night, where midfielder Ruslan Malinovskiy scored in a 2-0 win.
There are not expected to be any further changes from the side that started on Friday night, however, with Felix and Bernardo Silva again joining Ronaldo in the final third of the field.
Ukraine possible starting lineup: Pyatov; Bolbat, Krivtsov, Matviyenko, Sobol; Marlos, Malinovskiy, Stepanenko, Zinchenko, Yarmolenko; Junior Moraes
Portugal possible starting lineup: Patricio; Semedo, Dias, Pepe, Guerreiro; Neves, Danilo, Fernandes; Bernardo, Ronaldo, Felix
We say: Ukraine 1-2 Portugal
It is a very tough one to call due to Ukraine's excellent form in the section. Portugal desperately need a result, though, and we just fancy the visitors to pick up three much-needed points courtesy of a narrow win.