Barnes' goal completed a fine recovery by Liverpool, who were surprised in the 11th minute when Christophe Bonvin gave Sion the lead after a mistake by Dominic Matteo. Robbie Fowler, making his first appearance in four games after an ankle injury, scored the equaliser 13 minutes later. Then Barnes, working hard in all areas, got forward again to ghost into the penalty box and head the winner on the hour.
The Sion goalkeeper, Stephan Lehmann, gave a superb show and, if it had not been for his heroics, his team would be going to Anfield in a fortnight's time in a far worse state.
The Liverpool manager, Roy Evans, decided to bank on Fowler after two fitness tests in Switzerland, with Stan Collymore dropping down to the substitues' bench.
Patrik Berger could have given Liverpool the lead with less than a minute on the Swiss clock, only to see his shot deflected for a corner. However, Matteo was left embarrassed after 11 minutes when Yvan Quentin played a long ball forward. Matteo played it too short to his goalkeeper, David James, and Bonvin scampered away to score.
Liverpool continued to live dangerously and Alain Gaspoz fired a shot over the top after a piece of slack play by Stig Inge Bjornebye. Steve McManaman saw a shot pushed away by Lehmann before Fowler equalised with a scrambled goal. Berger made close-range contact with Bjornebye's cross, Lehmann just managed to keep the ball out but Fowler was on hand to steer it home for his first goal in Europe.
Sion, unbeaten in the last two months following the arrival of their Italian coach, Alberto Bigon, almost equalised when John Scales was caught out of position, but Bonvin sent the ball wide of the post after being set up by Philippe Vercruysse.
Liverpool stepped up the pace and Lehmann again came to Sion's rescue by pushing away a free-kick from Bjornebye. Jason McAteer latched onto the rebound, only to see his shot deflected for a corner. Bjornebye floated it in and Barnes sent a glancing header into the corner.
Sion: Lehmann; Gaspoz, Quentin, Wicky, Lukic, Vercruysse, Bonvin (Vincze, 80), Sylvestre, Lonfat, Zambaz (Chassot, 67), Milton. Substitutes not used: Borer (gk), Buhlmann, Colombo.
Liverpool: James; Matteo, Bjornebye, Babb, McAteer, Scales, McManaman, Berger, Fowler (Redknapp, 68), Barnes, Thomas. Substitutes not used: Warner (gk), Ruddock, Collymore, Kennedy.
Referee: A Lopez Nieto (Spain).Reuse content