In temperatures above 35 degrees Celsius (95F) with high humidity, David Rudisha then led a strong Kenyan contingent to a series of top-notch middle-distance performances that even deprived Ethiopian legend Kenenisa Bekele of a winning start to the season.
However, it was 2004 Olympic 100m gold medallist Gatlin who hogged the early limelight, pipping Asafa Powell by a head at the line and insisting he had the top of the podium at this summer's London Games firmly in his sights.
Powell, Jamaica's former world record-holder, got off to a flying start but Gatlin stuck with him and came through at the end.
"You've got to take track and field as a soap opera with spikes on," Gatlin said of his return to the circuit and mixed welcome back from fans and pundits.
"Everybody wants to see great competition. They've watched the Usain Bolt show for a couple of years, they want to see someone else in the mix and I'm happy to step up and be in the mix as well.
"I want everyone to know Justin Gatlin is back and I want the Olympic title."
There was certainly no such sparkling performance from Bekele, who laboured to seventh in a race dominated by Kenyan duo Augustine Choge and Eliud Kipchoge.
Bekele, coming back from two years of nagging calf and knee injuries and admittedly training at under 100 percent, was quick to blame his stop-start training regime.
"I missed one week of training and I had to take two, three days of rest," said Bekele, who is aiming to do the 5000-10,000m double at the London Games.
Choge's victory was indicative of an evening's athletics when Kenya won all six middle-distance events.
Rudisha, the world champion and world record holder in the 800m, looked in complete control as he strolled to a facile victory in the two-lap race in a very fast 1:43.10.
"That's a very good time for me," Rudisha said of his world leading time. "I know all the athletes want to beat me but I am well prepared to face the challenge.
"Great 800m runners like (Seb) Coe failed to win an Olympic gold but I will do my best to make it."
Olympic champion Pamela Jelimo was given a scare in the women's 800m by Ethiopian pretender Fantu Magiso.
Jelimo was third at the bell and the Ethiopian teenager kicked with 250m to go to build up a substantial lead on the Kenyan.
But Jelimo, recently crowned world indoor champion in Istanbul, reeled her in to win in 1:56.94 in a thrilling race.
World silver medallist Silas Kiplagat led home four other Kenyans in winning the 1500m in 3:29.63, Olympic champion Asbel Kiprop finishing at 0.15sec.
Circuit veteran Paul Koech led a Kenyan one-two in the 3000m steeplechase, but double world distance champion Vivian Cheruiyot (8:46.44) was made to work all the way to hold off Ethiopian rival Meseret Defar by 0.05sec in the 3000m.
"That was a great race, like an Olympic final," said Cheruiyot. "The last metres were like a 100m race, very, very close and really fast."
Allyson Felix produced a stunning upset in the women's 100m, the American three-time world 200m champion clocking 10.92sec to beat home Jamaican rivals Veronica Campbell-Brown and Shelly-Ann Fraser-Pryce.
"It was very good to get one over Campbell-Brown, especially in the 100m," beamed Felix, who enjoys the remarkable record of never having lost in Doha in eight appearances.
Felix's compatriot LaShawn Merritt, the reigning Olympic champion who served a 21-month doping ban, bagged the 400m race in 44.19sec, while fellow American Walter Dix, the double world silver sprint medallist, wrapped up the 200m in a convincing 20.02sec.
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