Championship leader Toprak Razgatlioglu dominated the opening World Superbike free practice session at San Juan, Argentina. 

After a 35 minute delay due to local technical issues, WorldSBK FP1 got underway with championship leader Razgatlioglu first out of the pits. 

Several riders elected to stay in pit lane early on due to large amounts of sand and dust covering the track. Those included Kawasaki team-mates Jonathan Rea and Alex Lowes. 

Razgatlioglu then returned to his Pata Yamaha garage without setting a flying lap, while Michael Van Der Mark began setting the pace ahead of Ducati riders Scott Redding and Michael Rinaldi. 

Redding, who is making his first ever appearance at the San Juan Villicum circuit then went half a second faster than his future team-mate Van Der Mark. 

Redding improved by another four tenths on his next effort to set a 1m 41s flat. With 15 minutes gone Razgatlioglu went P2, while title rival Jonathan Rea went tenth on his second flying lap. 

As track conditions continued to improve, Razgatlioglu set an impressive sub 1m 40s lap to go quickest by over five tenths. 

With half the session gone, Razgatlioglu’s advantage over Rea and Lowes was a stunning eight tenths of a second. That gap got as high as a full second before Rea closed it down to just under two tenths. 

Rea momentarily got ahead of Razgatlioglu with two minutes remaining, however, the 24 year-old’s penultimate effort moved the benchmark forward once again as he became the only rider to set a sub 1m 39s lap in the session - went over three tenths quicker than Rea in the process. 

Razgatlioglu then went even quicker on his final lap, a lap that put him half a second clear of his Kawasaki rival, before Redding jumped ahead of Rea late on for second. 

Chaz Davies made his return after missing the last two race weekends in Jerez and Portimao. The GoEleven Ducati rider was eighth fastest.

World Superbike San Juan, Argentina - Free Practice Results (1)
1Toprak RazgatliogluTURPATA Yamaha1:38.524s
2Scott ReddingGBRAruba.It Ducati+0.501s
3Jonathan ReaGBRKawasaki Racing Team+0.544s
4Alex LowesGBRKawasaki Racing Team+0.774s
5Isaac VinalesSPAOrelac Racing Kawasaki+0.940s
6Garrett GerloffUSAGRT Yamaha+1.065s
7Michael RinaldiITAAruba.It Ducati+1.112s
8Chaz DaviesGBRGoEleven Ducati+1.157s
9Alvaro BautistaSPATeam HRC+1.313s
10Andrea LocatelliITAPATA Yamaha+1.429s
11Leon HaslamGBRTeam HRC+1.460s
12Axel BassaniITAMotocorsa Ducati+1.506s
13Michael Van Der MarkNEDMotorrad BMW WorldSBK Team+1.614s
14Tito RabatITAKawasaki Puccetti+1.647s
15Leandro MercadoARGMIE Honda Racing+1.797s
16Samuele CavalieriSPABarni Ducati+1.905s
17Eugene LavertyIRLMotorrad BMW WorldSBK Team+2.764s
18Kohta NozaneJPNGRT Yamaha+3.578s
19Christophe PonssonFRAGil Yamaha+4.232s
20Marco SolorzaARGPedercini Kawasaki+5.270s
21Luciano RibodinoARGPedercini Kawasaki+5.884s