PRAGUE, Czech Republic - Samantha Stosur snapped her four-match losing streak to progress into the second round of the J&T Banka Prague Open after compatriot and No.3 seed Daria Gavrilova was forced to retire after suffering a right foot injury with the scoreline poised at 6-4, 3-6.

The injury had been a sudden one as Gavrilova, having served two double faults to open the deciding set, stretched for a backhand to go down 0-40 in the first game - and, wincing in pain, was unable to continue.

However, it did not detract from Stosur's imperious initial form. The 34-year-old had lost to her decade-younger compatriot at the start of the year in Sydney 6-4, 6-2, and trailed 1-2 in the overall head-to-head - but had been the victor in the pair's only clay meeting to date, 5-7, 6-4, 6-3 in last year's Strasbourg final.

Today, the 2010 Roland Garros finalist's clay prowess and power advantage were evident from the outset - and, over the course of putting together a lead of a set and a break, there was nary a falter. Striking her famed forehand with confidence and accuracy, Stosur whipped three winners from that wing in the first game alone, and proceeded to bully her less imposing opponent around the court with a barrage of winners struck with every variety of angle.

By contrast, Gavrilova was unable to get into a real groove, leaking errors when she tried to be aggressive but playing into Stosur's hands when she took a step back. Better length from the 24-year-old reduced a 1-5 deficit to 3-5, but was insufficient to save the set - and when, a few minutes later, she faced points to go down a 0-3 double break in the second set, it looked as though there was no way back.

The Sydney runner-up is renowned for her tenacity, though, and it was at this point that she began to employ more of her variety to disrupt Stosur's game. A net rush elicited an error on the pass from the 2011 US Open champion, and with a second serve ace to hold, Gavrilova was back in the match both physically and psychologically.

As Stosur began to spray a series of errors to concede her lead, Gavrilova became more vocal in her exhortations - and creative with her patterns. In the seventh game, she began to alternate drive backhands down the line with high, looped backhands cross-court that exposed her opponent's rigidity on that wing.

The World No.57 was able to keep within touch of her rejuvenated opponent, navigating long deuce tussles to hold for 3-3 with a brilliant serve-and-volley play and breaking back for 5-4 as she rediscovered the range on her forehand - but some brilliant defensive play from Gavrilova in the subsequent game, including a pinpoint lob to reset the point and a forehand pass at full stretch, would put the younger Australian over the line.

With the stage set for a thrilling decider, the nature and timing of the injury was an unfortunate anticlimax - but, having come into the tournament with just a 3-9 record in main draws in 2018, Stosur will be glad to have a chance to get her year on track. In the second round, she will face either home favorite Denisa Allertova or veteran qualifier Patty Schnyder.