Wrexham manager Phil Parkinson was left questioning the application of VAR after his side's valiant FA Cup run came to a dramatic end against Chelsea. The League One side pushed the Premier League giants to the limit in a six-goal thriller, but the game turned on its head when George Dobson was sent off following a VAR intervention, leaving the Red Dragons to fight through extra time with 10 men.Chelsea survived a major scare to defeat Wrexham in a dramatic encounter that required extra time after finishing 2-2 after 90 minutes. Wrexham appeared on the verge of an upset when Callum Doyle put them ahead in the 78th minute. However, the Blues found a late lifeline through defender Josh Acheampong, who levelled the scoring in the 82nd minute.In the 93rd minute, VAR intervened to send off Dobson following a heavy challenge to halt a rapid counter-attack, giving the visitors a numerical advantage just before the match headed into extra time.The momentum shifted afterwards as Garnacho struck in the 96th minute to give Chelsea the lead. Brazilian forward Joao Pedro then sealed the victory, firing home a fourth goal in the 120+5th minute. Chelsea now move forward in their quest to unseat reigning champions Crystal Palace, who famously defeated Manchester City in last season's final.Parkinson expressed his frustration after the final whistle, believing his side were on the verge of a historic upset before the dismissal. Speaking to BBC Sport, he said: "In the second half I think we were the better team and I was confident we were going to win. The referee gave a yellow. I'm not sure of the rules, it's the first time we've had VAR and it has to be clear and obvious to overturn it. I think the referee could have just kept it at a yellow."Despite the eventual 4-2 defeat, Wrexham proved they can compete with the elite. Goals from Doyle and an early strike from Sam Smith kept the Welsh side in the hunt throughout a frantic 120 minutes of football. Parkinson was glowing in his praise for the effort shown by his players against Liam Rosenior’s side."I'm very pleased with the way we acquitted ourselves tonight," Parkinson added. "We showed a lot of good aspects to our play and played some great football. We weren't just coming here to stop Chelsea - we believe we can play. We were frustrated not to come in at half-time ahead. The lads have given a lot tonight and to play extra time with 10-men is really hard."The match was a pulsating spectacle that saw Wrexham lead and then fight back to equalise through Doyle after Chelsea had momentarily taken control. Even with a numerical disadvantage, the hosts refused to lie down, creating several openings that could have forced a penalty shootout or even a shock victory at the Racecourse Ground.Reflecting on the missed opportunities in the closing stages, Parkinson noted: "We wanted to have a real go in the second period and we had some great chances. We had moments even with 10 men and the lads have to take a lot of credit tonight. I said at the break in extra time there are still going to be chances for us. Unfortunately we didn't take one but we have to take a lot of heart from that performance."Add GOAL.com as a preferred source on Google to see more of our reportingWhile the defeat marks the end of their FA Cup journey, the performance has reinforced the belief within the squad that they are destined for higher levels. Defender Doyle admitted the red card was the turning point but insisted the focus now shifts back to their primary goal of climbing the football pyramid.Addressing the team's long-term ambitions, Doyle told BBC Sport: "It is a tough one to take against a top side. I thought we did really well until the last part of the game. The sending off didn't help us. It is a big test, and they're a big side in the big leagues, and it is a good test for us against top players. We have another game on Tuesday, so we have to keep going. Hopefully, that is the target [promotion], but we have just got to stick at it."