Zhou Yuelong needed all 11 frames to beat Xu Si in their third-round qualifier at the 2021 World Championships.
Xu went two up with heavy scoring breaks in both frames, with a 90 following 95.
Zhou then hit back with two frames of his own, levelling with an unanswered break of 84, before Xu made it 4-2 in his favour.
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His opponent and countryman pulled back yet again, before Xu hit 78 to find himself just one frame from victory, but a tough-fought 10th frame - Xu grabbed 67 in a single visit before Zhou squeezed by with 73 - set the match up for an 11th-frame decider.
For all the tension at the finale, it took just one single 71 break for Zhou to go through.
Veteran Nigel Bond could not fight his way past younger rival Matthew Selt, as he was defeated 6-5.
Scott Donaldson also needed every frame to get past Dominic Dale, with Liam Highfield's game with ElliotSlessor needing a re-rack in the final frame.
In the first result from the day's later games, Kurt Maflin ran out a 6-4 winner against Jak Jones.
Qualifying results, Saturday 10 April
- Zhou Yuelong 6-5 Xu Si
- Matthew Selt 6-5 Nigel Bond
- Scott Donaldson 6-5 Dominic Dale
- Liam Highfield 6-5 Elliot Slessor
- Kurt Maflin 6-4 Jak Jones
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