Jakub Smrz denied Jonathan Rea a clean sweep of the Wednesday Portimao World Superbike test timesheets on his very last lap of the afternoon session.

Rea, riding in his new Castrol Honda colours, had dominated the two track sessions and looked set for a perfect start to 2011 after successfully repelling the afternoon challenge of Carlos Checa, Tom Sykes and rookie Eugene Laverty.

However Smrz - second fastest to Rea in the morning - put the new Liberty Ducati team ahead as he leapt from seventh to first place by 0.173sec. Prior to that 25th and final lap, Smrz had failed to improve on his morning time.

Smrz, just 13th in last year's world championship, set a best lap of 1min 43.503sec, which compares with the official Portimao WSBK race lap record of 1min 42.772sec, set by Max Biaggi in last year's event.

Behind the top two, new factory Yamaha rider Laverty made extraordinary progress as he improved from 14th in the morning to third place and just 0.204sec from Smrz in the afternoon.

While Smrz improved by 0.61sec, Laverty slashed over two-seconds from his morning lap time.

Tom Sykes showed Kawasaki had been wise to retain his services for 2011 with a confident fourth on the new ZX-10R, making it four different manufacturers in a top four covered by just 0.267sec.

First of the 'repeat' bikes was the Althea Ducati of Checa, who almost matched Laverty progress as he rose from just 15th in the morning - after a fall from his 1198 - to fifth in the afternoon.

Checa was the only rider other than Rea and Smrz to lead the afternoon session, when he briefly replaced Rea with just over an hour to go but lost ground in the closing stages.

Reigning world champion Biaggi began the test with third in the morning on his factory Aprilia, then didn't improve for much of the afternoon, until a late burst promoted the Italian star to sixth.

Another Roman, Alstare Suzuki's new signing Michel Fabrizio, claimed seventh place and was the final rider to break into the 1min 43s on Wednesday. The former factory Ducati rider had been fourth fastest in the morning.

Smrz's team-mate Sylvain Guintoli, Biaggi's team-mate Leon Camier and Sykes' rookie team-mate Joan Lascorz completed a top ten covered by 1.249sec.

BMW Motorrad (Leon Haslam and Troy Corser) is the only factory WSBK team not present and the S1000RRs present in Portugal, of BMW Italia riders James Toseland and Ayrton Badovini, were left outside the top ten.

Former double world champion Toseland recorded 12th and 11th in the two sessions, with Badovini 13th and 16th.

Also looking for clear progress on day two will be Noriyuki Haga, just 12th for the PATA Aprilia team, and Rea's team-mate Ruben Xaus, who finished day one in 13th place out of the 16 riders present.

Laverty's Yamaha team-mate, fellow rookie and former MotoGP star, Marco Melandri, appeared to struggle for strength in his healing shoulder and was left 16th and then 15th in the two sessions.

Testing at Portimao continues on Thursday and concludes on Friday.

A second official pre-season test will be held at Phillip Island, Australia, on February 21-22. The first round of the new season takes place at the same track on February 27.