It's the penultimate race for the Challengers of the Red Bull Air Race World Championship and all the pilots will be looking to collect as many points as possible to make sure they're at the season finale in Indianapolis.
The Challenger Cup takes each pilot's top four finishes and calculates their points, from there the six highest scoring pilots will compete at the season finale.
Six of the Challenger Class pilots will face off over the stunning Douro River in Porto and will want to show their rivals why they should be the one to watch. Here's how they line up for this weekend's racing.
Current position: 1st
The current Challenger Class Champion is sitting pretty at the top of the standings. He has raced three times this season (Abu Dhabi, San Diego and Budapest) and claimed two wins and a second place. This will be his chance to put even more space between him and the chasing pack as Daniel Ryfa, in second, and Luke Czepiela in third are not racing here in Porto.
Current position: 4th
Kevin Coleman has had a mixed season so far. In his four races to date in 2017 he has finished fifth, second, seventh and third. He is frustrated with his results and can't seem to get any momentum going. However, he is extremely confident and will want to push himself up the rankings. The fact that the season finale is in the US will mean he'll want to perform well to guarantee his place in front of the home fans, but this will add pressure to his performance.
Current position: 6th
Chiang has only competed in four Red Bull Air Races, but is already showing that he is a contender in the series. Throughout the season he has been posting strong, quick times in the Free Practice sessions and Qualifying, but he always seems to let the pressure get the better of him on Race Day. That was until Kazan, where he took the win in fine style. If he can do well here in Portugal he might do enough to claim a cockpit seat at the final race.
Current position: 7th
Astles has only raced three times this season, with her best performance being a third place at the season opener in Abu Dhabi. She will want to get back to her best and ensure her spot in Indianapolis. Astles will have to be at peak performance, but has proved her grit and determination before and will be pushing hard in Porto.
Current position: 8th
Murphy is another pilot that has only had three races so far this season. After he finished fourth in Abu Dhabi he had a long wait until his second race of the season. He had a five-month wait until he raced again in Kazan, where he had the double header of the rescheduled Chiba race and the Kazan round. He collected a third and a fifth in those races and he is on the same points as Chiang and Astles, all of whom will be looking to get an advantage to ensure their spot in the final. These three have everything to play for.
Current position: 9th
Genevey will be racing for the fourth time in his Air Race career in Porto. He, like Chiang, has impressed with his results, but his two fourth place finishes and a sixth see him bottom of the standings – this is due to how competitive the Challenger Class is this season. Genevey, however, is only four points away from the top six and he has been fastest in Qualifying, so if he can keep his cool, he has the chance to give his season that final boost.
The Challengers will be racing this weekend in Porto. You can follow all the action, live, right HERE!