The #1 BMW M4 GT3 EVO completed 205 laps of the Algarve International Circuit and finished 35.545 seconds clear of the #78 Maniti Racing Green Ferrari of Ryan van de Grijp and Marlon Duczek. Dániel Oláh and Norbi Kiss completed the GT3 podium for SZESE E-Sport, 49.105 seconds behind the winner.

Impulse Racing took the Porsche Cup victory with Pascal Costa and Rafał Szołtysek, while Konrad Zerebiec and Milosz Smuk won GT4 for Team Checkmate Wolak Group.

Grid-and-Go sticks to its plan

Koch had put the #1 BMW on GT3 pole, beating van de Grijp by just 0.06 seconds, and Grid-and-Go adopted one of the more conventional strategies once the race began: four fresh tyres at each of its seven stops.

Others were more aggressive.

The #44 Falken Simracing Team BMW emerged as an early threat after James Beumee skipped tyres at the first pit cycle. But connection problems subsequently cost the car significant time and effectively removed it from the fight at the front. Beumee and Niclas Heide nevertheless recovered to fourth, finishing on the lead lap and only 57.041 seconds behind the winner.

Grid-and-Go, meanwhile, kept executing its more conservative strategy. Koch and Haase led 177 of the race's 205 laps, resisting the alternative tyre approaches employed by their rivals.

Maniti briefly closed the gap when it attempted a no-tyre stop later in the race, but the advantage proved short-lived as van de Grijp lost time on the older rubber.

By the final stint, Haase had enough margin to bring the BMW home without a direct fight. He crossed the line 35.5 seconds ahead of Maniti, with SZESE third and Falken completing its recovery in fourth.

Koch described the performance afterwards as "a flawless race" and played down the significance of the championship situation.

"For us we don't really look into the championship, for us we want to win every single race we drive," he said.

BS+COMPETITION hit by costly black flag

The result was particularly significant because Grid-and-Go had arrived in Portugal level on points with the #89 BS+COMPETITION BMW.

Jordy Lopez and Lucas Hermann had scored 56 points across the opening three rounds, identical to the #1 crew, but their Portimão challenge unravelled during the second sequence of pit stops.

BS+COMPETITION received a black flag for speeding on pit exit while running fourth. The resulting stop-and-hold, combined with penalties already owed, kept the BMW in pit lane for more than 80 seconds and dropped it outside the overall top 20. Further contact penalties followed before the finish.

The #89 eventually recovered to 13th in GT3, one lap behind the winner.

The championship consequences, however, are less dramatic than the raw scores suggest because the series applies a drop-score system to the opening five rounds.

With each entry's lowest result discarded, Grid-and-Go leads the official post-Portimão GT3 standings with 58 points, two ahead of BS+COMPETITION on 56. The #89's three-point Portimão result is currently its dropped score. Maniti sits third on 50 points.

Late splash gives Impulse the Porsche Cup win

The Porsche Cup contest remained unresolved much deeper into the race.

Grid-and-Go's #901 Porsche, Impulse Racing and championship leader Bleu Mercure Esport all spent time in contention, with traffic, tyre management and different pit windows repeatedly changing the effective running order.

Rafał Szołtysek kept Impulse in the fight through the middle portion of the race, while Grid-and-Go's challenge suffered a setback when its #901 lost time in contact near pit exit. With approximately 40 minutes remaining, Bleu Mercure held a 10-second advantage over Impulse.

The decisive difference came at the final stops.

Bleu Mercure's Maxence Godiinho took tyres during a 36.8-second stop. Costa stayed out longer in the #915 Impulse Porsche before making a 12.8-second fuel-only splash with around 15 minutes remaining.

That 24-second difference put Costa back on track with approximately 13 seconds in hand, enough to secure the class victory by 10.7 seconds.

Costa described the race as "wild" afterwards and credited Szołtysek's combination of pace and tyre preservation, saying his team-mate "was flying" while still managing the rubber.

Bleu Mercure finished second, with the #901 Grid-and-Go Porsche third.

The result tightened the Porsche Cup title fight without dislodging Bleu Mercure from the championship lead. After the drop score is applied, the #932 holds 56 points, while Grid-and-Go and Impulse are tied on 52.

Final stop swings GT4 towards Team Checkmate

Pit strategy was equally decisive in GT4, where Team Checkmate Wolak Group finally ended Team75 Bernhard by SimRC's run of three consecutive victories.

Zerebiec started the #488 Porsche Cayman from class pole and built an early advantage, although a two-tyre strategy later brought Byte.Collino Max back into contention.

By the closing stages, Smuk and Ivan Llenderoso were fighting directly for the lead. Llenderoso moved ahead and held a two-second advantage with around 40 minutes remaining, putting the #444 Byte.Collino Max Porsche in a strong position before the final stops.

That was where the race changed.

Llenderoso's final service kept the #444 stationary for 57 seconds. Smuk stopped five minutes later and spent 16 seconds less in the box, emerging comfortably ahead.

Llenderoso reduced the gap during the closing laps but ran out of time. Smuk took the chequered flag 2.9 seconds ahead to give himself and Zerebiec their first GT4 victory of the season.

Smuk was quick to credit his team-mate afterwards.

"I'm not the fastest in the team... The track isn't made for me, so I needed to do as much as I can to stay in that first position," he said.

Team75's unbeaten run ends

For Team75 Bernhard by SimRC, Portimão was a sharp reversal after winning each of the opening three GT4 rounds.

Its problems began just 14 minutes into the race when Adam Isaksson's #475 Porsche made contact with the #445 Byte.Collino Pro car in traffic at Turn 6. The resulting repairs took almost 17 minutes and left Team75 nine laps down inside the opening hour. A later pit stop in which the team failed to refuel compounded an already difficult race.

Isaksson and Gareth Higgins eventually finished 13th in class.

Despite that result, Team75 retained the official championship lead once the drop-score rule was applied. Its three Portimão points are discarded, leaving the team on 60 points, six clear of Byte.Collino Max. Team Checkmate Wolak Group moves to fourth on 46 following its victory.

With four rounds completed, Grid-and-Go leads GT3 by two points, Bleu Mercure leads Porsche Cup by four and Team75 remains six clear in GT4. The lowest result from the first five six-hour races can be discarded, while the 12-hour Silverstone finale must count.

The championship continues with the 6 Hours of Adelaide on 4 October before concluding with the 12 Hours of Silverstone on 31 October.