Madrid - Novak Djokovic enhanced his credentials as the greatest threat to Rafael Nadal winning a 12th French Open title next month after he beat Dominic Thiem on Saturday to reach the Madrid Open final.
If Nadal overcomes the talented Stefanos Tsitsipas later on Saturday, it will be the Spaniard and Djokovic in Sunday's final, in what could prove a dress rehearsal for the title match at Roland Garros too.
World number one Djokovic's 7-6 (7/2), 7-6 (7/4) win over Thiem was far from comfortable, the Madrid crowd treated to two exhilarating sets of baseline tennis, but the Serb found his best in both tie-breaks.
In those pressure moments, Thiem, who saved two match points in beating Roger Federer in the quarter-finals, was unable to respond, even if he ran the top seed close enough to suggest he will be a serious contender again in Paris, where he was runner-up to Nadal last year.
Since taking a month off after winning the Australian Open, Djokovic has stuttered, enduring early exits in Indian Wells, Miami and then Monte Carlo.
But Thiem met the 31-year-old close to his best, delivering a timely reminder of why he has won the last three Grand Slam titles and will hold all four concurrently by winning his 16th at the French Open.
Djokovic conceded an early break when a short forehand hit the tape but struck back for 3-3, matching a Thiem drop-shot in kind before his opponent patted wide.
Thiem had a break point at 4-4 but it was Djokovic who stormed clear in the tie-break, winning the point of the match with, perhaps, the shot of the tournament.
Scrambling left into his backhand corner, Djokovic not only retrieved Thiem's approach but turned it into a brilliant lob that landed on the opposite baseline.
Disorientated, Thiem hit long to fall 4-1 behind and then again at 6-2 to hand Djokovic the set.
Thiem came again early in the second and broke in the sixth game, only to fail again to consolidate, Djokovic responding immediately for 3-3.
There was nothing in it until Thiem blinked again at 5-5 but this time Djokovic wavered, broken when serving for the match after coughing up a double fault.
Djokovic recovered his nerve in the tie-break, however, earning two match points and converting the first, when a tired Thiem framed a final backhand long.
Results from the ATP and WTA tournaments in Madrid on Saturday (x denotes seeding):
Novak Djokovic (SRB x1) bt Dominic Thiem (AUT x5) 7-6 (7/2), 7-6 (7/4)