Nico Terol and Maverick Vinales led the time sheets in Moto2 and Moto3, respectively, after the first day of a three-day test Tuesday at Valencia.
Terol's best lap was 1:35.926 on an Aspar Suter. Julian Simon was right behind at 1:35.951 on an Italtrans Kalex, while Pol Espargaro ensured a Spanish monopoly of the top three at 1:36.106 on a HP Tuenti Pons Kalex.
Brit Scott Redding was the first non-Spaniard, fourth at 1:36.337 on a Marc VDS Kalex. Takaaki Nakagami rounded out the top five at 1:36.443 on an Italtrans Kalex.
Terol's performance was an impressive rebound from a disappointing 2012 season. He won the 125cc World Championship in 2011, his fourth consecutive season in the top five in the introductory class.
But Terol finished 18th in the Moto2 standings in 2012 for Aspar, with a third place at the season finale in Valencia as his only top-10 result.
Vinales continued to show the promise for which he has been anointed the clear preseason favorite to win the Moto3 championship. He led at 1:40.715 on a Laglisse KTM, as the Austrian machines claimed the top four spots and Spanish riders also claimed the first three spots.
Luis Salom was second at 1:40.871, with Alex Rins third at 1:41.304. Malaysian rider Zulfahmi Khairuddin was fourth at 1:41.788, while German Jonas Folger was the quickest rider not on a KTM chassis, fifth at 1:42.093 on a Kalex-KTM.