Britain's Mark Cavendish will take a two-second advantage into Friday's final stage of the Tour of Qatar after regaining the leader's gold jersey.
The Manxman slipped 26 seconds behind Dimension Data team-mate Edvald Boasson Hagen on Wednesday's third stage.
But the Norwegian punctured 8km from the end of the 189km fourth stage to drop to fifth, 19 seconds off the lead.
His compatriot Alexander Kristoff won Thursday's stage to climb into fourth place, nine seconds behind Cavendish.
Kristoff beat Belgian Greg van Avermaet - who is second overall - in a sprint finish, with 2013 winner Cavendish fifth in a reduced bunch.
Intermediate and finish-line time bonuses are available on the final stage, and could yet determine the overall outcome.
Stage four result: (Al Zubarah Fort-Madinat Al Shamal, 189km):
1 Alexander Kristoff (Nor) Katusha 3hrs 57mins 12secs
2 Greg van Avermaet (Bel) BMC same time
3 Jacopo Guarnieri (Ita) Katusha same time
4 Sam Bennett (Ire) Bora Argon 18 same time
5 Mark Cavendish (GB) Dimension Data same time
6 Manuel Quinziato (Ita) BMC same time
7 Viacheslav Kuznetsov (Rus) Katusha +6secs
8 Soren Kragh Andersen (Den) Giant-Alpecin +8secs
9 Moreno Hofland (Ned) LottoNL-Jumbo +9secs
10 Michael Morkov (Den) Katusha same time
Leading overall classification after stage four
1 Mark Cavendish (GB) Dimension Data 10hrs 51mins 13secs
2 Greg van Avermaet (Bel) BMC +2secs
3 Manuel Quinziato (Ita) BMC +6secs
4 Alexander Kristoff (Nor) Katusha +9secs
5 Edvald Boasson Hagen (Nor) Dimension Data +19secs
6 Soren Kragh Andersen (Den) Giant-Alpecin +30secs
7 Sam Bennett (Irl) Bora Argon 18 +41secs
8 Sven Erik Bystrom (Nor) Katusha +49secs
9 Viacheslav Kuznetsov (Rus) Katusha +50secs
10 Michael Schar (Swi) BMC +58secs