Virat Kohli smashed a record double century to put India on top in the third Test against Sri Lanka, whose fielders wore anti-pollution masks in extraordinary scenes in a smoggy Delhi on Sunday.
Kohli cracked a career-best 243 but his sixth double century as captain was overshadowed on the second day after Sri Lanka complained about air pollution in the Indian capital, halting play three times.
The second session of the match was delayed more than 20 minutes as smog visibly worsened at Feroz Shah Kotla stadium and the umpires consulted the match referee and team doctors.
Sri Lankan fast bowlers Lahiru Gamage and Suranga Lakmal returned to the pavilion amid the drama, leaving the visitors short of fielders and prompting Kohli to declare India's first innnings on 536-7.
Sri Lanka coach Nic Pothas defended the decision to halt the match, saying players' safety is of "paramount importance".
"Obviously it is well documented that Delhi has high level of pollution. They had got extremely high at one point, we had players coming in at one point and vomiting," Pothas told reporters.
"There were oxygen cylinders in the dressing room. It is not normal for players to suffer in that way while playing the game.
"Under most circumstances we wanted to play cricket. We just wanted to have some clarity on the safety of players," Pothas said.
Sri Lanka were 131 for three at stumps, trailing the hosts by 405 runs.
Angelo Mathews, on 57, and skipper Dinesh Chandimal, on 25, were batting when bad light stopped play for the day.
Mathews, who returned to form with a fighting half-century, and Chandimal steadied the Sri Lankan innings with an unbeaten 56-run stand after pace spearhead Mohammed Shami struck with the very first ball to dismiss left-hander Dimuth Karunaratne.
Lanky paceman Ishant Sharma then trapped Dhananjaya de Silva lbw for one as the visitors took tea on 18-2.
Dilruwan Perera, who scored 42 after opening the batting in place of injured opener Sadeera Samarawickrama, then staged a gritty 61-run partnership with Mathews.
Both Perera and Mathews were given reprieves, on 16 and six respectively, after Shikhar Dhawan and Kohli dropped catches in the slips.
Perera was eventually trapped lbw by left-arm spinner Ravindra Jadeja as Sri Lanka slipped furthur.
- 'Virat didn't need mask' -
But the day belonged to Kohli, who recorded his second successive 200-plus score to pulverise the Sri Lankan attack after India started the day on 371-4.
He surpassed West Indies great Brian Lara to become the first international captain to register six double centuries. Lara had five.
Kohli, who started the day on 156 and batted over seven hours, combined with overnight partner Rohit Sharma, who scored 65, to put on 135 for the fifth wicket.
The skipper, who made 213 in India's thrashing of Sri Lanka in the second Test, pulled Lakmal for a couple to reach his milestone, raising his bat to acknowledge a raucous home crowd.
The Delhi-born star was finally trapped lbw off left-arm wrist spinner Lakshan Sandakan, who claimed four wickets in the innings.
"Virat batted close to two days, he didn't need a mask! We are focused on what we need to do. The conditions are the same for both teams," said India's bowling coach Bharat Arun.
"I don't think we were too worried about pollution. The BCCI (Board of Control for Cricket in India) schedules these matches and our job is to get the best out of our team. Focus is more on that," he added.
India lead the series 1-0 and need only a draw for a record-equalling ninth successive Test series triumph.