Simon Thornton and Tjaart van der Walt continued to slug it out at the top of the leaderboard as both men aimed for a first European Tour win at the St Omer Open. Press Association The two men came into the final day in a share of the lead but it was Irishman Thornton who made the first move, picking up a single shot to move to five under, one shot clear of Van der Walt. Thornton got off to a flying start with birdies at the first and third holes but a bogey on the fourth gave him just a single shot lead after six holes of his closing round. Van der Walt had a birdie and a bogey on the card this morning but with 12 holes still to play, the tournament was very much within reach for the South African. Another of the overnight leaders, Baptiste Chapellan, was a further shot back after bogeying the third while Englishmen Chris Lloyd and Seve Benson were also on three under. German Max Glauert and Dane Jeppe Huldahl, at two and one under respectively, were the only other players under par.