Oscar Piastri won the Qatar Grand Prix Sprint after being allowed through on the final straight by team-mate Lando Norris as McLaren sealed a one-two.
Norris led from the start and appeared set to seal his second Sprint win of the season before slowing down on the approach to the chequered flag to let Piastri past, repaying the Australian for a similar - but less dramatic - gesture in the Sao Paulo Grand Prix Sprint earlier in November.
The move was risky given Mercedes' George Russell was following closely behind, but Norris pulled off the manoeuvre to ensure McLaren took maximum points and extended their Constructors' Championship lead over Ferrari to 30 points heading into tomorrow's full-length contest.
Carlos Sainz and Charles Leclerc limited the damage by taking fourth and fifth for the Italian team, the latter passing Lewis Hamilton on lap 13 having lost out to the Mercedes at the start.
Hamilton had to settle for sixth after a brilliant start that also saw him overtake newly crowned world champion Max Verstappen, who dropped to ninth on the opening lap before pulling a position back to take the final point in eighth.
Nico Hulkenberg drove an impressive race to come from ninth on the grid to finish seventh, extending Haas' advantage over Alpine and RB in the tight battle for sixth in the Constructors' Championship.
Norris makes risky repayment to Piastri
Before Norris' challenge for the drivers' title had been ended by Verstappen last weekend in Las Vegas, Piastri had shown willingness to help his team-mate by letting him through with two laps to go in the Sprint at Interlagos.
Given McLaren's desperation to ensure parity for their two young and talented drivers throughout the season, it wasn't surprising that a returning of the favour might be suggested, but the manner of it was the surprise.
After Piastri jumped Russell for second at the start, Norris generously dropped back to offer DRS assistance to his team-mate as the Mercedes applied heavy pressure throughout the 19-lap contest.
It appeared as though Russell was too close for McLaren to attempt to pull off a switch, but on the way out of the final corner, Norris slowed to let Piastri through, with the pair crossing the line just 0.136s apart, with the Mercedes a further 0.274s back.
"It was probably a bit closer than what I was wanting, but I planned to do it since Brazil," Norris said.
"It's just what I thought was best. It's probably a little bit sketchy. The team told me not to do it but I thought I could get away with it, and we did.
"Honestly, I don't mind. I'm not here to win Sprint races, I'm here to win [grand prix] races - and a championship, but that's not gone to plan. But I did the best we could and I look forward to tomorrow."
Piastri claimed the second Sprint win of his career, winning the shortened race in Qatar for a second successive year.
"It was about defence for the whole race," the Australian said. "I had a good start and good Turn One but didn't quite have the pace. I think I killed the front a bit early on.
"I was struggling a bit for the rest of the Sprint but some great team work. Without that help, it would have been a much more difficult Sprint. Nice to have a McLaren one-two."
Elsewhere, the most entertaining battle was between future team-mates Hamilton and Leclerc, who duelled over a series of corners at the start of lap 13 and made minor contact before the Ferrari emerged in front.
Verstappen lost three places on the opening lap as he struggled for grip, and surprisingly could only pass Alpine's Pierre Gasly for the final point as Hulkenberg remained out of reach.
Sky Sports F1's live Qatar GP schedule
Saturday November 30
4pm: F2 Sprint Race
5.15pm: Qatar GP Qualifying build-up
6pm: QATAR GP QUALIFYING
8pm: F1 Academy: Race One
8.45pm: Ted's Qualifying Notebook
Sunday December 1
10.55am: F1 Academy Race Two
12.15pm: F2 Feature Race
2.30pm: Grand Prix Sunday: Qatar GP build-up
4pm: THE QATAR GRAND PRIX
6pm: Chequered Flag: Qatar GP reaction
7pm: Ted's Notebook
Formula 1's season-ending triple-header continues this weekend with the Qatar Grand Prix, live on Sky Sports F1. Get Sky Sports F1 or stream with NOW
