LONDON (AFP) - Juande Ramos admitted Tottenham will have to improve dramatically if his reign as UEFA Cup king is to continue for a third season.

Ramos's side slumped to a lacklustre 1-0 last 16 first leg defeat against PSV Eindhoven and face a premature exit unless they raise their game in the return in Holland next Wednesday.

It is an unusual position for Ramos who has grown accustomed to success in the UEFA Cup after winning the competition two years in a row with Sevilla.

The Spanish coach is adamant his players are superior to those of the Dutch league leaders, but there was scant evidence of that at White Hart Lane on Thursday.

Jefferson Farfan punished a horrendous first half mistake by debutant defender Gilberto to score the decisive goal and PSV could easily have won by more.

Ramos conceded Spurs will only progress to the quarter-finals if they can recapture the form they showed to win the League Cup last month.

"When you lose by 1-0 it is not too bad but we will have to play a lot better in the second leg. The barometer is very low. If we want to stay in the competition we will have to improve," he said.

"We had the best players on the pitch but PSV had the best result. We have to accept that. After this match it is going to be very difficult."

Farfan's 34th minute winner left Spurs nursing a Wembley hangover that is beginning to concern Ramos.

Since winning the League Cup against Chelsea, the north London team have been thrashed by struggling Birmingham and produced a tepid display against PSV.

Ramos allowed his players to let their hair down for two days after the final, but they can expect a tough time in training from now on judging by their manager's mood.

"The last two matches we haven't played as well as we could. We played well against Chelsea but we've lowered our tempo since then," he said.

"Of course we celebrated for two days but after that we started training normally. The only problem has been Birmingham and PSV played better than us."

Tottenham's hopes of a second leg revival were hardly helped when Jermaine Jenas was stretchered off with a twisted ankle in the second half.

The England midfielder could be sidelined for several weeks if scans reveal serious damage.

"He has twisted his ankle. We will have to wait at least 48 hours to see how he is improving," Ramos said.

There were no excuses for Spurs, who lost at home in Europe for only the third time in 59 matches.

Ledley King and Jonathan Woodgate were back from injury and, after the League Cup was paraded to the home fans before kick-off, the stage was set for another glory night.

But PSV were the better side from start to finish. The breakthrough they deserved came when Gilberto dwelt in possession on the edge of the penalty area.

Peru striker Farfan robbed him and buried a fine strike past Paul Robinson.

Steed Malbranque led the Spurs response with two raking drives before Robbie Keane forced a brilliant stop from PSV goalkeeper Gomes.

Farfan was denied a second by Robinson before a late, unsuccessful spell of Spurs pressure.

PSV coach Sef Vergoossen knows his team are in a strong position but he warned them not to get complacent.

"We can say the starting basis for the next leg is very good. However there are no guarantees," he said.

"There can still be a lot of danger as we saw here. We are in a good position but it is never guaranteed.

"It took too long before we started playing football but especially in the second half we played very well. I felt 2-0 was a lot closer than 1-1 ever was."