Former Uefa Cup winners Spurs reached the competition's group stages after beating Slavia Prague on aggregate.
Keane scored his first goal of the season
Spurs have had an uncertain start to the season and this was a display that highlighted their goalscoring problems.
Chief culprit was Robbie Keane, who might have done better with a header and a shot in the first half.
After the break Spurs were unsettled as Slavia came into the game, but with 10 minutes left Keane scored his first goal of the season with a drilled shot.
When Hossam Ghaly chested the ball to Keane there looked little danger for Slavia, but the Spurs striker quickly worked himself some space, before arrowing a low shot into the corner of the net.
In stoppage time Keane had a header ruled out for offside, while his striking partner Mido should have added a second only to miss with a headed effort.
Slavia proved more obdurate opponents than they had in the first leg.
Matus Kozacik played well in goal for the visitors, while former Birmingham defender Martin Latka was impressive in central defence, notably when he headed clear under pressure from Calum Davenport just before the hour.
But as with Spurs, Slavia lacked a cutting edge in attack to capitalise on plenty of second-half possession.
Jenas had scored Spurs' goal in that first leg in Prague and the former Newcastle midfielder was arguably the home side's most impressive performer.
Jenas made a series of powerful runs and his ability to travel at speed with the ball caused Slavia problems.
In Spurs' very first attack both Jenas and Mido tried to connect with Pascal Chimbonda's cross, but neither player was able to get sufficient purchase on the ball.
From the resulting corner Davenport flicked on, an effort that Keane was unable to turn in as the ball zipped off the sodden turf.
Midway through the first half Keane headed into the sidenetting from a difficult angle.
Chimbonda also played well for Spurs and late in the first half he served up another cross for Mido, who was foiled by some brave goalkeeping by Kozacik.
Four minutes before the interval Keane should have put Spurs ahead when he was teed up by Danny Murphy, but the Republic of Ireland striker's effort was comfortably saved by Kozacik.
The visitors attacking opportunities were limited but Pavel Fort drew a save from Paul Robinson with a flicked header.
Just after the break Matej Krajcik tried his luck with an ambitious shot that momentarily worried Robinson before the effort went over the bar.
Krajcik's initiative prompted a sustained period of pressure from Slavia and Robinson had to get down quickly to save David Hubacek's shot.
Spurs manager Martin Jol:
"If you don't score you make it hard for yourself.
"Robbie Keane is a special player, he can score out of nothing.
"Mido lives off crosses and we don't have that for him at the moment."
Slavia coach Karel Jarolim:
"We wanted to try and keep the scores level for as long as we could and make Spurs nervous.
"We could have taken the lead and 1-0 would have made the end more dramatic.
"Tottenham had chances but the golden ones came near the end.
"But overall I am very satisfied with the performance of my team."
Tottenham: Robinson, Chimbonda, Dawson, Davenport, Young-Pyo Lee, Jenas, Murphy (Ghaly 71), Zokora, Ziegler (Tainio 63), Keane, Mido.
Subs Not Used: Cerny, Huddlestone, Ifil, Assou-Ekotto, Charlie Lee.
Goals: Keane 80.
Slavia Prague: Kozacik, Krajcik, Latka, Suchy, Hubacek, Janda (Vlcek 63), Jarolim, Hrdlicka (Kalivoda 74), Svec, Svento, Fort (Necid 78).
Subs Not Used: Divis, Dosoudil, Gaucho, Aracic.
Ref: Tommy Skjerven (Norway).