Gilbert's Deceuninck-QuickStep team held a masterclass while Belgian national champion Yves Lampaert secured his last place on the podium while Florian Senechal and Zdenek Stybar returned home in a group of pursuers in the top seven.
Defending champion Peter Sagan (Bora-Hansgrohe) had to settle for fourth place after fading in the last 20 km of a tense 117th edition of the Queen of Classics.
Gilbert, Politt, Lampaert and Sagan were part of a select group of six men who entered the business end of the race with a one-minute advantage over the group of pursuers.
Also the Belgian Wout Van Aert (Team Jumbo-Visma) and Sep Vanmarcke (EF Education First) were part of the decisive move, but they were the first to vanish following a series of accelerations.
Gilbert has divided the leading group in two with a big bold in the notorious five-star section of the Carrefour de la Arbre de pebbles in the last 16 km.
Both Sagan and Politt held the wheel of the Belgian veteran before Vanmarcke and Lampaert closed the gap after Van Aert had returned, feeling the toll after a previous race accident.
It was the impressive Politt, already very present in the main rest day, to pass the next major attack with 14 km remaining, with only Gilbert able to follow him.
The mechanical problems put an end to the possibilities of Vanmarcke, while an exhausted Sagan was rapidly riding the squares, leaving Lampaert the only pilot able to return to the fold.
But with team-mate Gilbert on the road, Lampaert came in third place – raising his arms high as he returned home 13 seconds less on the winner of the day before savagely celebrating with his compatriot at the center of the velodrome.
It was Gilbert's fifth victory in the Cycling Monuments after his previous triumphs in Lombardy (2009, 2010), Liege-Bastogne-Liege (2011) and Ronde van Vlaanderen (2017). The 36-year-old just needs a victory in Milan-San Remo to secure a historic coup de grace for the biggest one-day sporting events.
Sagan crossed the finish line for fourth place at 42 seconds and just before a group of pursuers who was brought home by the French Senechal. The absolutely dominant Deceuninck-QuickStep team placed a fourth rider among the top seven in Zdenek Stybar in what was a good day at the office for team manager Patrick Lefevere.
The pre-race favorites Greg Van Avermaet (CCC Team) and Oliver Naisen (Ag2R-La Mondiale) returned home in the group of pursuers but just out of the top 10 after another fierce battle on 29 sectors and 54.4 km of pebbles.
The freezing temperatures and a strong headwind made it difficult to start the Hell of the North without any interruption, managing to keep the better part of two hours, despite the regular moves that shorten from the front to poor results.
With the first hour at an average speed of 45.5 km / h, the Dane Magnus Cort was particularly active for Astana after a previous solo break from his Kazakhstan team-mate Dimiriy Gruzdev.
The Italian expert Marco Marcato (United Arab Emirates) was joined by the former winner of the Roubaix Juniors, the Dane Mads Pedersen (Trek Segafredo). But the duo's advantage never stretched more than 30 seconds before the race returned together with the remaining 200 km.
A trio composed of two other Danes to Casper Pedersen (Team Sunweb) and another junior junior, Mads Wurtz Schmidt (Katusha-Alpecin), as well as the Belgian expert Jurgen Roelandts (Movistar) established a 40-second lead after 60 km.
Once again, this move has been thwarted. Trek & # 39; s Pedersen tried his luck on at least two other occasions before, at the end, a move of nine runners opened a significant gap after about 80 km of tense driving.
Leaders include Belgian Tim Declercq (Deceuninck-QuickStep) and French Damien Gaudin (Total-Direct Energie), who finished fifth in 2013.
The break took about 10 seconds to play with a group of pursuers that included Belgian champion Lampaert, German rangy Politt and Italian Matteo Trentin (Mitchelton-Scott) while the pilots hit the first of 29 cobbled sections at Troisvilles with the group 30 seconds back.
Team Sky, Lotto Soudal and Bora-Hansgrohe set the time on the front of the pack while the race entered its cobblestone phase after losing the previous moves that were formed in windy winds after a cautious opening.
Soon, the two moves came together to form a group of 23 pilots with a gap of 50 seconds while the race crossed the second cobbled sector between Briastre and Viesley, dedicated to the late Michael Goolaerts, the Belgian pilot who died of a cardiac arrest during last year's edition.
With the duo Quickstep Lampaert and Declercq, the European champion Trentin, the French duo Gaudin and teammate Adrien Petit, and veteran Matti Breschel (EF Education First) all involved, the strong break has kept his gap of 50 seconds crossing the first handful of cobbled sectors.
Back with the package both Alexander Kristoff (United Arab Emirates Team Emirates) and Andre Greipel (Arkea Samsic) punctured, while Trentin's moving place came to an end after a back plate in Sector 26.
It was all over for the rest with 120 km remaining after the seventh section of cobbles, shortly after a touch of wheels in the group brought down a group of pilots including the defending champion Sagan.
Some heavy time from Senechal, the nth former junior champion Paris-Roubaix, has divided the group and captured some famous pilots including Sagan, the Naesen form and the Norwegian Kristoff, who collected a & # 39 another image and soon disappeared from the dispute.
In the frenetic scenes that precede the notorious five-star cobblestone sector of the Arenberg Trench, the Belgian Iljo Keisse (Deceuninck-QuickStep) fell after a collision with a sign just before the two packages returned together.
On the infamous Arenberg Trench, the first of three cobbled five-star sections, Belgian cyclocross star Van Aert stuttered, making sure that Sagan took an evasive action, before joining forces with the Australian Heinrich Haussler (Bahrain Merida) 45 seconds back.
The impressive Belgian standard Stijn Vandenbergh (Ag2R-La Mondiale) drove into the Arenberg forest to maintain a thin advantage by exiting the 2.3 km section while Van Aert continued his pursuit.
Van Aert's troubles continued when, after changing his bikes, he crashed into a curve to the right in front of Hornaing's longest pebble section. The 24-year-old got back on his bike, but was driven by a leader for over a minute and had another battle in his hands with the unpredictable ride of wandering team cars.
The young Belgian Teisj Benoot experienced these first-hand travails: the pilot Lotto Soudal, after joining forces with Van Aert after his accident, was brought to the hospital in tears following an alleged collision with the Jumbo team car – Van Aert's view.
With 65 km remaining, a potentially decisive move materialized when Politt attacked in a feeding zone and was joined by Philippe Gilbert (Deceuninck-QuickStep) and Rudiger Selig (Bora-Hansgrohe). Capturing and surpassing the lone leader Wesley Kreder (Wanty-Gobert), the trio set a 25-second gap before the Orchids section of cobbles.
When Sagan accelerates and exceeds Van Aert, Sep Vanmarcke (EF Education First) and Lampaert, it seems that the winning break was formed, especially when Selig's deadwood was eliminated with 52 km from the end.
Behind, Van Avermaet and Jasper Stuyven (Trek Segafredo) attempted overtaking, but their attacks were matched by the patrol of Stybar, who was protecting his two QuickStep teammates.
The group of six men from the Slovakian champion Sagan, the German Buck Politt and four Belgians at Gilbert, Lampaert, Van Aert and Vanmarcke, saw their advantage extend beyond a minute with eight cobbled sections.
With just over 20 km away, the break splits into two following a Gilbert acceleration. Sagan and Politt followed the veteran's wheel, while behind the remaining three Belgians are demoted. Eventually Lampaert sank, riding clear with Vanmarcke while Van Aert, hearing the blow after his previous accident, seemed to vanish.
Meanwhile, the main pursuer group was losing numbers with Trentin among the famous pilots to be removed. Vandenbergh led the pursuit for teammate Ag2R-La Mondiale Naesen, but the gap had stretched over a minute before the decisive five-star final of the Carrefour de l 'Arbre.
Lampaert and Vanmarcke rejoined the leaders with 18 km remaining, but this last, which was already riding the EF Education First team-mate Sebastian Langeveld following an accident at the beginning of the race , saw its possibilities suffered by a mechanic.
Even Sagan has vanished, the defending champion has looked at a pale imitation of his former bold from 12 months before. As in last year's final, a clear favorite in Gilbert led an outsider into the Silvan Dillier mold at the velodrome before the final sprint.
Twenty-five-year-old Politt, who finished seventh in his third Roubaix last year, was forced to drive the sprint when Gilbert drove inside the last corner to win an impressive feat but inevitable: the 700th victory in the history of his team and the 23rd of another season.
With only the Milan-Sanremo trophy missing from his cabinet, we are waiting for Gilbert and his team Deceuninck-QuickStep to go all in for La Primavera next spring – provided that the defending champion Julian Alaphilippe, another QuickStep pilot, gives the his ascent.
The focus now shifts to the Ardennes classics in the Liege-Bastogne-Liege construction on April 28th. With two wins from three Monuments so far this season – and the man that Alaphilippe will probably present – we can expect more from the team that created an absolute cobblestone lesson in the enchanted Northern Hell of Sunday.