Hyundai shares have soared to a record high while rival Honda still has supply chain woes after the earthquake.
Japanese automaker Honda has slashed production and are still calculating the recovery of parts makers, making it difficult to give earnings forecasts.
South Korean rival Hyundai has seen its shares, up more than a third this year, increasing seven per cent to a record high after posting results.
"Hyundai has been emerging as an alternative to Japanese cars, shaking off its image as a maker of cheap cars," said Lee Dong-jin, a fund manager at KTB Asset Management.
"It's now seeing some benefits from increasing production at overseas plants while the world took a hit from the financial crisis."
Hyundai, helped by a popular line-up of new models which have been selling strongly in top markets China and the United States, said its net profit rose 47 per cent to 1.88 trillion Korean won ($1.7 billion) in the first quarter, compared with 1.28 trillion won a year ago.
However disruptions to Honda's supply chain have resulted in its net profit for January-March falling 38 per cent to 44.55 billion yen ($541.8 million).
Operating profit fell 52 per cent to 46.21 billion yen compared with an average estimate of 103.1 billion yen from 15 analysts.
A survey of 15 analysts put Honda's operating profit for the full year to March 2012 at 394 billion yen, down from 569.8 billion yen in the business year that just ended.
Honda said it would not provide an outlook for the new business year until at least May as it struggles to measure the speed of its recovery.
Hyundai outperformed its global peers in the last quarter thanks to popular models such as the Sonata mid-sized sedan and the Elantra compact in the United States, South Korea and other markets.
"The first quarter earnings are very good and the outlook is even rosier but one risk factor is exchange rate trends, since export markets account for a large part of Hyundai Motor's earnings," said Kang Sun-sik, chief analyst at Woori Asset Management.
The momentum is set to pick up in April-June as Hyundai and its Kia affiliate enjoy higher pricing, partly helped by the output cuts in Japan.
"Before the earthquake, concerns lingered about price competition, but we can pretty much rule that out now," said Yoon Pil-joong, an analyst at Samsung Securities.
Hyundai and Kia are targeting combined sales of 6.33 million vehicles this year, which could be on par with Toyota's sales, which analysts forecast at 6.3 million to 7 million.
While the supply bottleneck of certain specialty parts such as microcontroller units made by Renesas Electronics Corp has also hit some automakers outside Japan, domestic brands such as Honda have been hit hardest, with output remains at half the level planned before the quake.
Honda and Toyota Motor have forecast a return to normal production by the end of 2011, but said they do not know how quickly volumes will pick up.
"Japanese car makers have failed to provide a clear picture of how they are going to get back on their feet," said Park Sang-won, an analyst at Eugene Investment & Securities in Seoul.
"They may lose their leadership in the global auto market to Korean car makers for the longer term."
The slump in auto production accounted for about half the record 15.3 per cent fall in Japanese factory output in March, the government has said.
The earthquake has not only splintered the industry's complex supply chain, but has forced a delay in vehicle launches.
Honda had been scheduled to begin selling a new hybrid station wagon based on the popular Fit subcompact in Japan a week after the quake, while Toyota has also postponed the launch of wagon and minivan versions of the Prius.
The shortage of Japanese cars and the long wait for consumers could hurt their market share in key regions such as the United States and China as some car buyers opt to shop at competing brands, one analyst said.
"There's no way to know how this will play out in the medium to longer term," said Takaki Nakanishi, an auto analyst at Merrill Lynch Japan Securities.
"While supply is tight through the summer, some sales will shift to other brands such as Hyundai.
"We'll only start to get a sense of whether this trend is temporary or not towards the end of the year."