Last season's UEFA Cup finalists survived a slump in form and some anxious moments in the Czech Republic tonight to make Thursday's fourth round draw.

Teplice, trailing 3-0 from the first leg, could only muster a consolation goal from Jiri Masek, although Celtic's Chris Sutton hobbled off with an injury to put him in doubt for the weekend.

With John Hartson, Ulrik Laursen and Shaun Maloney already out for the season, Hoops boss Martin O'Neill would have been worried to see Sutton limp out in Teplice, with Sunday's Tennent's Scottish Cup quarter-final against Rangers next on the agenda.

It should have been much easier after the 3-0 win at Parkhead last week - but Celtic made hard work of it.

Up until the 35th minute goal the biggest concern to Celtic had been from a pre-match power cut, which delayed kick-off by 10 minutes, and the persistent fall of snow.

To add to the drama both sets of players struggled to stay on their feet early on.

John Kennedy and Rilke Emil both appeared to slip as they tussled for the ball but referee Tom Hennig Ovrebo awarded Teplice a free-kick and booked the Celtic youngster.

Alan Thompson attempted to put the tie well beyond reach in the seventh minute with an audacious long-range shot which was plucked out of the air by Tomas Postulka as it headed for the top corner of the net.

Vladimar Leitner evened up the booking count with a terrible challenge to bring down a flying Didier Agathe as he burst down the touchline.

Thompson again threatened the Teplice goal in the 15th minute with another long-range free-kick which missed out his team-mates and ran through to a relieved Postulka.

Rilke theatrically tumbled in the box under the challenge of Jackie McNamara after Tomas Kuchar's cross - but the referee looked disinterested as Kennedy cleared the danger.

Kuchar's 24th-minute mistake when his mistake gave Henrik Larsson sight of goal but his effort was saved by Postulka with Sutton lurking.

The Teplice keeper again did well, four minutes later, to hold the Swede's powerful 30-yard free-kick after he had been flattened by Rada Karel.

Robert Douglas looked a tower of strength and coped with everything that came near him in the box with the help of his solid defence.

That was until the 35th minute when a poor header from Stanislav Varga went straight to Masek and he blasted the ball through the Celtic goalkeeper's hands from 18 yards.

The goal gave Teplice hope but a reckless challenge from behind from Tomas Hunal on Sutton deservedly earned him a yellow card.

Varga attempted to make amends shortly before the break but his header, from Thompson's free-kick, went straight at Postulka.

O'Neill's decision to field arguably his strongest side soon became justified as his men battled to fend off the pressure from the revitalised Teplice side.

But Lambert should have destroyed their new-found confidence in the 52nd minute.

The midfielder exchanged passes with Thompson but instead of shooting he got caught in two minds and his weak cross was saved Postulka, who had left his near-post free.

Celtic breathed a huge sigh of relief moments later when Rada headed Kuchar's corner over from six yards with Douglas flapping in the box.

Kennedy then had to clear desperately after Kuchar's cross had hit Hunal in the box and fallen kindly for the visitors.

Rilke was the next man booked on the hour for a foul on Stilian Petrov as O'Neill glared anxiously from the technical area.

The Celtic boss looked concerned again in the 70th minute when Sutton picked up his injury and was forced to hobble off, to be replaced by Stephen Pearson.

Ironically Celtic put together their best move of the match as the Englishman left the field as Agathe picked out Larsson and his volley was well saved by Postulka.

The Swede should have eased their nerves in the 78th minute - but Postulka again thwarted him with a desperate dive.

But despite being below par, Celtic were assured of their place in the fourth round of the UEFA Cup and all thoughts now turn to that, Sunday's Old Firm clash and Sutton's injury.

Teams

FK Teplice Postulka, Leitner (Styvar 87), Rada, Tesarik, Verbir (Jakub Kolar 90), Dolezal, Skala, Hunal, Masek, Rilke (Ryska 74), Kuchar.

Subs Not Used: Patrik Kolar, Sigmund, Kostecka, Vorisek.

Booked: Leitner, Hunal, Masek, Rilke, Verbir.

Goals: Masek 35.

Celtic Douglas, McNamara (Valgaeren 84), Balde, Larsson, Thompson, Sutton (Pearson 68), Lambert, Agathe, Petrov, Varga, Kennedy.

Subs Not Used: Marshall, Sylla, Wallace, Beattie, Smith.

Booked: Kennedy, McNamara. Agg (1-3)

Att: 10,000

Ref: Tom Ovrebo (Norway).