Groves exchanged equipment with Alpecin-Deceuninck teammate Xandro Meurisse on the side of the road before fighting his way back to the peloton and claiming his second stage of the race ahead of Bryan Coquard (Cofidis).
Despite the suitable terrain on offer for the breakaway and sprinters, the 174-kilometre stage still featured another chapter in the battle between general classification leader Primoz Roglic (Jumbo-Visma) and Remco Evenepoel (Soudal Quick-Step).
In the end, both riders took a second off one another from the intermediate sprint bonuses on offer to leave the gap at 10 seconds ahead of the final stage in Barcelona.
Though the day’s journey to Molins de Rei only featured one categorised climb – the Alt de la Creu d’Aragall – in the final 30 kilometres, there was still some undulation throughout the first 140 from Martorell.
Soudal Quick-Step’s Mattia Cattaneo and Ilan van Wilder made several attempts to get in the early breakaways but found themselves closely marked by Jumbo-Visma as the first intermediate sprint approached after 66 kilometres.
With no breakaway established, Roglic was able to beat Evenepoel and add an extra second to his overall lead shortly before Egan Bernal (Ineos Grenadiers) crashed out of the race.
Fausto Masnada (Soudal Quick-Step), Carlos Verona (Movistar), Geoffrey Bouchard (AG2R Citroen), Oscar Onley (Team DSM), Simone Velasco (Astana Qazaqstan), and Jonas Gregaard (Uno-X) would eventually get away midway through the stage, though their one-minute advantage over the peloton would dwindle by the time of the Alt de la Creu d’Aragall.
Marc Soler (UAE Team Emirates) was the first to launch a significant counter-attack near the top of the climb, the Spaniard taking 20 seconds on the peloton in an attempt to oust Mikel Landa (Bahrain Victorious) from fourth overall.
Roglic and Evenepoel would soon catch Soler on the descent, engaging in a game of cat-and-mouse before the Belgian took the sprint spoils in Palleja to cut his overall deficit back to 10 seconds.
Jumbo-Visma would go on to control the pace as the finish line approached, with Groves departing the peloton for a swift bike change with Meurisse in the remaining five kilometres.
As the 24-year-old battled back to the bunch, Soudal Quick-Step made their move for Evenepoel in the final 600 metres, but the world champion’s efforts could only earn him fifth place as Groves stormed home ahead of Coquard, Ide Schelling (Bora-Hansgrohe) and Maxim van Gils (Lotto Dstny).
"Number one was nice but a second stage win this week, so I'm very happy," Groves said after the race.
"At about seven or eight kilometres to go I felt my rear tyre had a slow leak. I wasn't sure whether to stop or not. I was thinking maybe I should do the sprint with it pretty flat. But in the end, I've got to thank my directors – they decided that I should do a bike swap with Xandro.
"So, at about 5km to go I stopped and he gave me his bike. Then I got to come back and with the help of Nicola, I got back to the front for the sprint.
"I was very lucky that I had them there. We didn't have time to do a full bike change, so we had to just sacrifice one guy. It was a headwind until the final corners, so we stopped in the headwind and got back in the crosswind. Thankfully it was a reduced bunch, and the race wasn't going too fast."
Stage 7 will see the peloton travel 135.7 kilometres to Barcelona, and SBS VICELAND and SBS On Demand will have all the action LIVE from 9:30pm (AEDT) on Sunday, March 26.
